#63 Safari is at it again – capping 1P cookie lifetimes and redefining 3rd party!

The Measure Pod
The Measure Pod
#63 Safari is at it again - capping 1P cookie lifetimes and redefining 3rd party!

This week Dan and Dara discuss the recent changes announces from Apple on the way they will be copping 1st party cookie lifetimes – even if being being set via server-side GTM. What imapct will this have, and what difference will it make to most people? That and if Sessions is a better metric than Users (again)…

WebKit GitHub documentation on the 7-day lifetime cookie capping – https://bit.ly/3uWXUpI.

Simo Ahava’s post on LinkedIn https://bit.ly/3WqHulb.

In other news Dan runs and Dara will (or has been?) drinking in the emerald isle!

Follow Measurelab on LinkedIn – https://bit.ly/3Ka513y.

Intro music composed by the amazing Confidential – https://spoti.fi/3JnEdg6.

If you’re like what we’re doing here, please show some support and leave a rating on Apple, Spotify, or wherever really.

Let us know what you think and fill out the form https://bit.ly/3MNtPzl, or email podcast@measurelab.co.uk to drop Dan and Dara a message directly.

Quote of the episode from Dan: “new versus returning is, in my humble opinion, been kind of redundant for a couple of years now at very least.

Quote of the episode from Dara: “we’ll throw the machine learning kitchen sink at this just to try and salvage this users metric



[00:00:15] Dara: On this week’s episode, we cover Safari’s latest step in its quest to completely destroy our beloved cookie, with this having a particular knock on effect on anybody who has been using server-side GTM and CNAME cloaking.

[00:00:28] Daniel: If you’re curious as to how to migrate over to server-side Tag Manager alongside migrating to GA4 and all the other fun technological stuff that comes with that. Reach out to me and Dara, there’s a form in the show notes if you have any questions or get through to us at measurelab.co.uk and there’s a couple of forms in there and we’ll be happy to talk to you about how to migrate. Hope you enjoyed the show.

[00:00:47] Dara: Enjoy.

[00:00:48] Dara: Hello and welcome back to The Measure Pod, a podcast for people in the analytics world to talk about all things analytics and data. I’m Dara, I’m CEO at Measurelab.

[00:00:57] Daniel: I’m Dan, I’m an analytics consultant and trainer also at Measurelab.

[00:01:01] Dara: So this week we’re going to talk about an upcoming change that Safari has announced to do with first party cookie lifetimes. So as I always do, I’m going to hand it over to you to, to give the announcement Dan, and then we can dig a little into it and talk about some of the ramifications and some of our thoughts around it But I’ll let you be the bringer of the facts.

[00:01:18] Daniel: Oh, is that right? You’re letting me explain a very convoluted and complicated subject. You’re so generous.

[00:01:25] Dara: I’ve given you the honour, yeah.

[00:01:26] Daniel: Okay, I’ll take the honour. Well, I’ll do my best. We’ll link off some documentation around this and you know, just as a heads up, we by no means experts, we are not browser developers or engineers. We don’t work behind the scenes, we work more around the analytics implementation and the kind of Google Tag Manager side. So let me just say what it is and then we can talk about how it’ll affect things like marketing and analytics because obviously that’s the world that we live in.


[00:01:48] Daniel: So as you teed up quite nicely, Dara, this is an Apple thing, this is a Safari thing and more broadly it’s WebKit. So WebKit is the sort of browser technology that powers all browsers on Apple phones not just Safari, but also things like Chrome and Firefox and anything that runs on an Apple device actually needs to go through WebKit. And so what WebKit have done is they’re actually throwing a bit of a spanner in the works. We’ll talk about what it’s going to do in a second, but in terms of capping cookie lifetimes life. But what it’s actually doing is changing the definition of first and third party, which is the biggest thing that most people are getting a bit annoyed about. So let me just say what it is, so they are currently capping any first party cookie lifetime to seven days. That shouldn’t be news to most people listening, but it might be news to some of you. But anything on any WebKit browser, anything on Safari specifically, caps first party cookies to seven days specifically obviously in our context Dara, the GA (Google Analytics) cookie.

[00:02:35] Daniel: A lot of people up to this point have been using something like server-side tag manager to quote, unquote, work around that seven-day life time issue they see with the Google Analytics cookie using a server side tag manager, they can set the Google Analytics cookie without a dependency or without that seven day window implemented. However, that was the long version, the short story is that those cookies that will be set via the server-side Tag Manager will also be capped at seven days. Fundamentally WebKit are making an update which is yet to be released at the time of recording that will mean that any first party cookie set by a third party, that’s by something that has a different IP address than the host will be capped at seven days. Specifically referring to analytics, that will be the GA cookie set in server-side tag manager.

[00:03:18] Dara: And this is probably where our lack of expertise in kind of this web technology, server-side technology, at least ours personally, I’m not suggesting that people we work with don’t know a lot more about this than we do, but we don’t know what other effects this could have on, depending on what infrastructure people have. It could be that genuine first party, first context cookies are going to be restricted to the seven-day lifetime as a result of this. And that’s, again, I’m going to put a big disclaimer out there, I’m not saying that is the case, I don’t know. But yeah, absolutely the work around people have been using with server-side GTM is a big obvious thing in the firing line, and I guess this was maybe on the cards, maybe people should have foreseen that this would happen, maybe they did?

[00:03:55] Daniel: Yeah, WebKit are doing a really good job of knocking down any new technology that comes along to kind of work around it. So whether that’s you know, from ITP, the first couple of rounds of ITP where it was, you know, limited third party cookies, then block third party cookies, then capped first party cookies, then affected local storage, and now we’re looking at first party cookies set in this context. But something you mentioned there, and I mentioned too actually in my long, very long-winded definition is that you said first party cookie in a first party context or a third party context, that’s the big thing that they’ve changed the definition of. So yeah, there’s lots of first and third parties in this explanation, so apologies if it’s super confusing but I’ve linked to all the documentation that we’ve had and we’ve read through so you can go through it a bit slower.

[00:04:33] Daniel: But the first thing is that the reason that people started using server-side Tag Manager or any server-side tracking implementation is because technically it’s your own server. So you can put a CNAME on your domain and it comes from a sub-domain. So you might have www.dan.dara, and then you might have gtm.dan.dara, and that is a sub domain of that regular domain and that’s where you would host your server. That’s where you’d host your server-side Tag Manager instance. And so in a sense, what would happen is this sub domain, let’s be do a bit more of a sensitive example like gtm.mywebsite.com will be setting cookies on mywebsite.com and that is a first party context. However, what they’ve decided to change is the definition of first party context there. And so rather than it just looking at the domain, they’re actually looking at the IP addresses of the domain that’s setting this cookie.

[00:05:20] Daniel: So it’s looking at the first half of the IP address, so it’s not super limited, but it’s looking at the first half of the IP address and if that first half of the IP address of the domain setting the cookie, or attempting to set the cookie, does not match the first half the domain of the host/the website, then it will be treated as a third party context. So even if you have this subdomain thing set up for Google Tag Manager, there is a chance there that you, this being hosted in the GCP and then your website not are going to come from two different domains. And then even if you’re using this subdomain, this CNAME cloak as they call it, and you’re setting up all this stuff, it’s still going to be treated as a third-party context and thus the seven-day lifetime will still occur. So I think that’s the biggest or most confusing change is they’ve decided to change the definition of first and third party contexts in the context of first party cookies.

[00:06:04] Dara: So the only way you’re going to be able to set a cookie, a first party cookie that can persist for longer than seven days will be if you’re actually setting it on your own domain, using your own server. So the IPs have to match, so it’d really only be for things like site functionality or anything that you’re kind of storing for features that users are using on the website. If it’s anything to do with communicating with a third party, whether it’s via GTM or anything else, then it’s going to be subject to this seven-day cap.

[00:06:34] Daniel: Yeah, exactly. And I just wanted to add in as well, like there’s been a lot of conversation around this online and especially in the circles that we mix with in terms of the analytics circles, those kind of analytics marketing circles. But I just wanted to kind of remind people that if you are not using server-side Tag Manager or any kind of server-side tracking, this will have no effect on you. It’s only for the people that have already moved to server-side tracking that will see a difference. But in a sense, when they move to server-side tracking, they undone a difference that was already there. WebKit setting a Google Analytics cookie with a maximum lifetime of seven days has been in place for a very long time. That is currently happening on your version of Google Analytics if you don’t use server-side Tag Manager right now. If you are using server-side Tag Manager, you’ve kind of worked around that or you’ve kind of undone that and you are setting the GA cookie for a lot longer than seven days. All it’s doing, is bringing it back together, so it’s just bringing that seven-day lifetime to both sides of that.

[00:07:24] Daniel: So it’s not like everyone’s going to notice a change. It’s not like everyone’s going to have something worse than they had before. It’s just for these people, you know, the kind of early adopters of server-side tagging specifically, they kind of temporarily had a gain in data quality, but they’re going to be brought back down to level with the rest of us soon enough.

[00:07:40] Dara: Thinking aloud, and maybe I’m being a bit daft here, so do feel free to tell me if I am, what happens if you have consent to set the cookie that lasts longer than seven days? Will this technology just rule that out completely, if you had consent to keep a first party cookie for more than seven days, how would you work with that with this WebKit restriction or can you?

[00:08:02] Daniel: You can’t really, so the seven-day lifetime restriction is based on a consented cookie. So you first of all have to get consent to write a cookie to the user’s device. Once you have that cookie, the browser’s limitations take over and sets that to a maximum of seven days. So you can ask and get consent, you can get as much consent as you like. You could ask the user to set a cookie on their device forever if you wanted to. It doesn’t change the reality of the technology not letting you go beyond seven days. And also the other thing with this is that like I said it’s no different to what people have got right now. So anyone on any WebKit browser that’s not using server-side Tag Manager has already got the Google Analytics cookie set to a maximum lifetime of seven days.

[00:08:38] Daniel: Just a bit more on that, when we say seven days, lifetime of seven days for a cookie, we’re not saying after seven days it is removed. What it is saying is seven days of inactivity, so if someone keeps engaging with your brand, every six days, so they come back to your website, they do something. That cookie lifetime is reset to seven days every single time they engage with your website. So it’s only of seven days of inactivity does then the cookie get removed. Like a lot of things, if they keep engaging with your brand more frequently, then you’ll be fine. But there will be some brand, some verticals, some industries where this is just a, like a big issue, you know, people don’t convert and engage every three days on every brand, you know?

[00:09:13] Dara: I’m thinking myself out of it as I’m about to say it, but I was going to say it’s a bit unfair on those industries because the seven days, it feels a little arbitrary in a way and it probably is. It’s probably like right, what’s a reasonable timeframe to keep that cookie, but seven days to a website where people are likely to be on several times a week, like, or even once a week if it’s a grocery, if it’s a Tesco website, seven days might be reasonable. If it takes you longer than seven days, then the cookie expires, but realistically, you probably will be on the site again. If it’s a cruise company or if it’s some kind of, you know, struggling to think of another example, where it’s something that you maybe would go on the site frequently, but like frequently being once or twice a year or once or twice, you know, a quarter or something like that. Then that seven days obviously is very different to you, but they’ve got to put these policies in place and I guess privacy legislators and privacy advocates aren’t going to be happy if they said, oh, actually seven days is a bit unfair on some industries so we’ll set it to 700 days instead. So seven is probably as good a number as any.

[00:10:13] Dara: But you’re right, this is not new. I mean, this change is new, but this change is only going to affect people who have tried to use this work around that that you mentioned. But I guess part of the point of this topic is that we had a conversation earlier about how these changes in technology, they don’t always necessarily filter through to some of the people who are, let’s call them like the beneficiaries of the data or the users of the data. So the people doing the marketing or even some of the people who are running the websites. Say you’re a website owner, smaller business and you’re spread very thin and you’re trying to do all the marketing yourself. You’re not necessarily going to keep up to date with all of the changes in browser technology, it’s hard enough for us to keep up, and this is kind of very directly related to what we do. And yet people continue to use the numbers in the same way. Or some people, I shouldn’t say this isn’t the case for everybody, but it’s often the case that the numbers get reported in the same way, regardless of any changes that happen to the technology that actually affects the way these numbers are collected and reported on. You know, with these changes, it’s obviously going to have a knock-on effect on metrics like users and new versus returning.

[00:11:20] Daniel: Yeah, and I think that’s the biggest thing to stress here, is that these numbers have been affected by technology from the beginning really. But it’s easier to explain behavioural changes or societal changes and to say, okay, well compared to 15 years ago, people use devices differently. People have more smartphones. 4, 5g, have come along and made these kind of micro moments more micro than they used to be, especially on a dial up internet. So like you can kind of grasp, or at least most people can grasp the fact that people engage with websites and the internet in a very different way now than they used to. What is hard to talk to and to talk about and to explain, especially to people using data to make decisions. So as you said there, Dara like, you know, practitioners, analytics people, analysts, marketers, whoever that beneficiary is. Specifically, it’s around the kind of behind-the-scenes stuff, so the technology. So, you know, you go in and you say, well, Firefox tracks data differently to Safari that does different stuff to Edge and Chrome.

[00:12:11] Daniel: It’s a really hard thing to grasp and explain, especially when numbers like users or visitors are so ubiquitous in the industry and everyone thinks they have a definition, or at least they might have an assumed definition of what that is. I do it all the time and it’s one of the things that I spend a lot of time in my training actually when I’m talking about Google Analytics or analytics in general, in any training context, is to not assume your definition of something is in actual fact, the actual definition. And it’s about kind of having this layer of critical thinking and saying, I’m lazy, and I will say, how many people came to the website last month? How many people saw this page or engaged with my campaign? The reality is there’s no possible way of measuring, you can’t track people, but we do have these things called users.

[00:12:47] Daniel: The next layer on top of that is that the definition of users changes over time too. Like this change from WebKit here we’re talking about, but also previous iterations of ITP from WebKit, Safari, Chrome. It’s not one definition, you know, users isn’t one thing and new versus returning is, in my humble opinion, been kind of redundant for a couple of years now at very least.

[00:13:07] Dara: I think what you’re saying, you could have summed that up really simply by just saying, bring back sessions. That’s what you meant, we all know it. We all know that’s what you really meant. No, but listen, you’re right and actually, like one thing on top of that, so not only have you got the changes in browser technology and cookie lifetimes, all of this has changed in recent years. But the calculation of users has changed within not just Google Analytics, but possibly other analytics tools as well. So you’ve got the changes in the underlying web technology to do with privacy and all the rest of it and the issue with cookies. But then you also have the analytics vendors potentially making changes to their definitions as well, in some cases to improve them, but whether they’re improving them or not, it’s changing them. And yet often the reporting of that metric just stays the same as if it’s been the same number forever even though in reality it hasn’t.

[00:14:00] Dara: And users, it’s not people, and as soon as you start to say to people, it’s a cookie on a device, you know most people just, their eyes glaze over a little bit and then they just think, oh yeah, he confirmed that’s people, and you think that’s not what I said.

[00:14:14] Daniel: Well, yeah and that’s without going into the depths of Google Analytics 4’s approach of using machine learning modelling to fill in those gaps too, where it becomes a big mess or a big, like ambiguous kind of unknown. This is the thing about users is that quite often these changes means that the number goes up because the cookies and users are less identifiable. And so every time someone comes back to the website, it’s a new user, it’s perceived as a new user. The whole count of unique users, is something that’s only ever going to go up not because necessarily you are getting more popular or doing more marketing. It’s actually quite often the fact that the technology kind of restricts down and then you end up tracking more of these things called users. But to your point, Dara, sessions is a good metric that isn’t going to be affected as much by things like this. The reason for that is sessions are quite neatly defined as sort of a bunch of interactions on your website or app with no gap between them, no break basically of interaction of more than 30 minutes.

[00:15:07] Daniel: And that 30 minute window can be customised. You know, that’s in the UI, most people don’t because they don’t know it’s there to be fair or they don’t have a better reason. But it’s quite nearly defined and you’re not going to have issues with cookies lasting, you know, less than 30 minutes, for example. And so we are probably not going to get to a point, I’ll be very surprised that we get to a point where we have to start questioning the value of the session. It is useful, sessions are becoming more useful than users, but I don’t want to concede on that, Dara, I don’t want to concede and let you win that sessions are more important or more valuable than users, but I think for me it’s more around having the definition or understanding what it is tracking and the small print, the limitations, the pros and cons. Then you can apply your own sort of business context to see whether that’s useful or not, whether that’s a KPI you know, or rather just an indicator, that’s up to you. But the thing that I try my hardest at is kind of showing you or telling you what they are, help you with defining them, and then you can make the assessment whether or not they’re important to your business or yourself. But I’m not going to say that users aren’t important or aren’t valuable anymore because if I admitted that now, I’d say basically for the last three to five years, they’ve been pretty much the same.

[00:16:05] Dara: Yeah, and it’s, you know, it is a tough one because I’m not equally, I’m not saying that we should just abolish users completely, but the reality is it’s becoming less and less reliable for various reasons. You mentioned kind of behavioural changes earlier as well, and like people are using more and more devices. Although actually saying that I might be using outdated information on that, maybe that’s stopped now, but there was a point where that number was just going up and up and up, but maybe it’s plateaued now. The fact is, you know, people are potentially using a work computer, personal computer, a phone, maybe people who play games, of which I’m not one, maybe they connect to the internet, the interwebs using their gaming box. So potentially that one person to go back to people wanting to report on people, it could be showing up as several users, then you’ve got technology changes, meaning that’s getting split further again. So I just feel like it’s getting further and further away, and then if you have non-consented users and you’ve got cookieless pings and you’re using machine learning.

[00:17:00] Dara: I don’t know, maybe the cynical part of me just thinks because there was that shift from sessions to users. There was a desire to move away from sessions because it wasn’t seen as being kind of useful enough compared to things like a user conversion rate and then all of this kind of shift towards privacy started and it was almost like the industry didn’t want to give up on this move towards users. And it’s kind of like, no, we’ll throw everything at it, we’ll throw the machine learning kitchen sink at this just to try and salvage this users metric. But I don’t know, maybe it’s just time to let it go.

[00:17:33] Daniel: You can’t let it go, not when everything’s built on this thing now, but look, we’ll see what happens, we’ll see what happens, users isn’t going anywhere, and it’s not one size fits all as well. And I think this is where pushing to a more advanced identity resolution or pushing that onto the website. So, you know, the obvious examples are things like Google and Amazon, everyone’s logged in on everything they do right? That’s a dream, you don’t need to worry about these things called cookies because everything is going to be tied to a logged in user at some point, or at least 99% of it is. So I think that’s where getting a login side of things, you know, the companies and the services that have a logged in element and getting more people to sign up for rewards or genuine positive gain and value.

[00:18:10] Daniel: I was actually on the Van’s website earlier today and they’ve got this whole kind of like Vans Family, they call it the Vans Family club thing, where you go in, you have a look at points and you can spend them, and it’s a whole portal. And again, I’m not saying they’re doing that for analytics reasons, but it is a good thing that’s not just sign up to an account to receive an email every month or a newsletter. It’s not that, it’s something completely different, it’s trying to incentivise that kind of one-to-one identity resolution or communication. But then for other companies you’re quite right though, don’t have that, they don’t have the high enough data volumes to get the sort of machine learning modelling. They don’t have any real need or want or drive or technology to get people to log in. They might end up just looking at sessions, right, because for them that’s more reliable of a KPI than users ever would be or could be.

[00:18:52] Daniel: But I think this is where too little information is dangerous because if we all just go in, and especially if you’re log into Google Analytics 4, it perceives users as the most important number there, and they might end up using that. So I think this is going back to my point, it’s like helping people understand the definition of these things is the most important because then they can make the decision that’s not down to the tool or the vendor to say this number’s important for you or blank it for everybody.

[00:19:13] Dara: But then we are back to something we said at the beginning, it’s tricky enough for us to keep track with all these changes and what they might mean. Like if you’ve done kind of a piece of historical analysis, you’re trying to go back and get your timeline of what changed, when, and what might have caused metrics to either increase or decrease for any particular, you know, reasons that aren’t just more or less people visiting a website. For your marketer or website owner who’s got a lot of other things to do, it is tricky keeping track of this and like you are right, obviously it’s down to the definition of what that metric is and not just now, but at different points in time. But that can be tricky to keep track of and that’s why certain things never change, do they? Conversions never change, sessions never change, within reason. Whereas users, I mean, it’s been all over the place, really.

[00:19:59] Dara: And I’m not, this is not just another attack on the users metric. But I guess what I’m saying is that it is tricky for somebody who, you know, analytics isn’t their day to day they’re looking at numbers, trying to act on them. They’ve got a management dashboard, or they’ve got a set of KPIs and they’re looking for movement in those KPIs. And you know, when that’s just one of many other dashboards that they’re looking at from various other parts of the business it’s tricky to keep that mental tally of, you know, what does users mean today? But that’s really the one that’s the most fragile, isn’t it? Because of all of these changes in cookies.

[00:20:32] Daniel: Without digging up too much of the past, because I know that we talked about sessions versus users way, way back, I think in the early days of the pod. But I think the outcome there, I’m going to call up again and I think there’s this halfway house and I think there’s this idea of session days, and I think that is under deduping or having a unique count of users per day. And it is more around sessions are limited by the definition, and the definition was curated many, many, many years ago, most definitely before smartphones. So the idea there is to say how many people, or rather how many users, how many devices, how many cookies, that kind of thing, visited the site per day. So it’s unique per day, and it’s just showing you how many days someone engaged with your brand. It’s a different number, it’s a different definition but I’ll link off to the documentation we did about session days because I think it could be really useful.

[00:21:17] Daniel: As long as the cookie lasts for the full day, you’re all fine. Again, it’s like the saying, the cookie has to last for the session, for a session to be tracked, of course. If a session lasts a day, that’s great. Right now, there’s no issue with analytics cookies being set for less than a day or 24 hours. So I think we’re all good here and then we are just looking at unique within days rather than unique across lifetimes, which becomes quite hard to do. So yeah I wonder if what your thoughts are on that, are session days acceptable still, are you still going to fight for the right to sessionize?

[00:21:46] Dara: I just think, you know, if it ain’t broke, don’t fix it.

[00:21:50] Daniel: What if it was already broke to begin with?

[00:21:52] Dara: Well yeah, I mean that’s the question, isn’t it? No, but look, I think it’s a really interesting, it’s an interesting point. We don’t have to just take the metrics that are provided in the overview reports either. So some kind of calculated metric unique to each business is reasonable because especially if you are, again, this is not a one size fits all approach because what we said earlier about if you’re a website where people will visit a couple of times a week, then very few of these cookie issues are a problem anyway as long as you have consent and correct, you know, correct consent based on those criteria that we’ve discussed previously on The Measure Pod, then it’s not going to be a problem for you. But if you’re in a business where someone’s only going to visit your website once a month, once every two or three months, then it’s a very different situation, so you might want to focus in on different metrics, depending on how affected you are by these different technology changes because it’s going to affect different websites to different degrees.

[00:22:45] Dara: If there’s one kind of key point to come from it, I guess it’s, you know, don’t just take the bog-standard metrics that are offered to you without understanding what they mean and how they might actually not work that well for your business. You know, take the time to kind of think a little bit about it and potentially use some kind of variation of a metric that’s there already, whether it’s session days, or whether it’s just sessions, or whether it’s something else entirely. Rather than just thinking, oh, if I log into GA it gives me a few numbers, I’ll just report on them.

[00:23:14] Daniel: I think that’s the thing, what we’re not trying to say to everybody is that you need to get very expensive analytics consultants to help out and define everything from, you know, the earlier stages of a business. And I know that’s not what you’re saying, Dara, but it’s more around, don’t just throw away something like Google Analytics or any analytics tool and say, I need to build my own numbers. I think it’s more around, you know, without just assuming that the tool or the platform knows best about your business, your brand, your website. To kind of ask that question of like, what is it that I want to do? What is it that we need to measure? And I think even if it’s just very simple around questioning things like there’s a hundred numbers in front of me, all of those cannot be KPIs. What are our KPIs? What are our key performance indicators? Even if it’s from a selected list and say, okay, five of these out of the hundred surely are going to be more important than the others.

[00:23:57] Daniel: I think it’s just about making a decision like that. I think just being thrown a bunch of data by a tool like Google Analytics can be overwhelming, but also I think then you end up kind of falling back and I know I have before, but I end up falling back and just saying, well, all of this must be important because otherwise, why would they show it to me. Why have they showed this number to me and not this other number? So yeah, I think it’s more around, you know, don’t worry, you don’t need to have this bespoke, tailored thing for every organisation. But I think it’s more around this critical thinking aspect of it and saying, well maybe this isn’t as useful as this other number, let me just use the other number. Even if the other number looks like it’s going crazy high or crazy low, maybe it’s not a KPI, maybe it’s just a PI, I don’t have an acronym for that one.

[00:24:36] Dara: I think we briefly skimmed over this earlier, but it’s probably worth just being really explicit about it, if these upcoming changes affect you. If you’re using server-side GTM to do the CNAME cloaking, if there’s a change in the IP address between the server setting the cookie and the server that is being set on, then it’s going to be capped at seven days. So what’s going to happen then is you’re going to see your user kind go up, as lots of people have done at various points in recent years when browsers have made these changes. So users will go up, user conversion rate will go down and then I guess a few other knock on effects. Obviously it’ll affect new versus returning, which is kind of a rubbish metric anyway. It’s probably going to mess up retargeting lists to some extent. You’ll have more people or well, more users supposedly going into remarketing lists, although they’ll be the same people potentially, and they’ll just be getting included across multiple cookie lifetimes. So your performance across those remarketing lists could drop down a little bit as well. And the extent to which this happens again, is going to be different depending on the nature of your particular audience and how frequently people visit your website.

[00:25:41] Daniel: Yeah, exactly. And specifically around GA4, that’s built with users in mind and every number in there has got some kind of skew towards users, like, average engaged sessions per user or average engagement time per user. My advice really, and again this is a bit of a niche audience we’re talking to here with server-side GTM, that have already implemented it. But a lot of people are going there, and this might be one of the reasons is that the numbers change. This isn’t the first time and it 100% won’t be the last time. The numbers will change based on a technological reason, nothing to do with you, your website or your marketing, and it’s just something to be aware of that can then happen. We’re flagging this one change that’s coming up, but like I said before, this has happened before and it’ll happen again.

[00:26:18] Daniel: So be mindful, maybe put little footnote in a dashboard or annotations if they ever decide to release those in GA4. But some kind of annotation just so that people don’t panic, so a lot of the people that might be the recipients of these reports and these dashboards might react in a certain way because of a factor they think will be their fault. When sometimes, and quite often the time is that the external factors, these technological factors or these behavioural factors actually have a bigger impact on this data than we might wish to believe.

[00:26:44] Dara: So do you think the other browsers will follow suit?

[00:26:46] Daniel: I don’t know, it’s hard to say, other browsers have followed a lot with the ITP framework, so who knows, there’s absolutely a reason that they could do this. If I know Google, Google Chrome specifically, they will take their sweet time doing it, they’re still delaying the deprecation of third-party cookies, and they’re the, well, I think they’re literally the last browser left supporting third party cookies. So, who knows? Who knows if it will happen? I have no doubt it will happen, but I don’t know if I’ll be around to see it.

[00:27:12] Dara: There’s no way to, if you wanted to allow cookies for longer than seven days, is there any way to override that as a user within Safari?

[00:27:20] Daniel: I have no idea, I don’t know, I don’t think there’s any way for the end user to set their own cookies. They can clear them and they can edit the fields. But unless you know specifically the terms, the cookie names and the values, I suppose you could type them in, but that’s a level of nerdy that even I’m not even part of.

[00:27:36] Dara: Obviously the browsers, at least in theory, or at least superficially they’re doing this for the good of the users and to protect privacy, but they’re kind of making that decision for people, aren’t they? And, you know for informed users, it’s nice to have the option to control it yourself.

[00:27:53] Daniel: Here’s the conspiracy theory side of me, but I think this is something we’re going to talk about in an upcoming episode, actually. But this is the SKAdNetwork 4.0 release that Apple have just rolled out and started rolling out. But that also covers web as well. So it’s an app and web attribution platform. This is the sinister side of it, but I think this is where Apple’s going, is they’re going to lock down their ecosystem so that they control all of this stuff, and then you have to go ask them for things like conversions and attribution windows and things like that so they can do the attribution for you. Because the whole point of tracking users is all about attribution modelling, right? It’s all about understanding the interactions that a user had leading up to a point of value, of a conversion, of a transaction or whatever. And so if Apple holds all the cards, they can make that what they want, you know, behind this wall guard, this black box.

[00:28:35] Daniel: So who knows, it might be kind of moving more and more towards this kind of ecosystem that’s worked for them from an app perspective. And they might be moving their web stuff over, at least that’s the movements they’re making with SKAdNetwork 4.0. That’s just my guess, that’s my guess. Let’s get a guest on, let’s have someone who knows what they’re talking about talk to us about it and maybe we can throw the question to them.

Wind down

[00:28:52] Dara: Yeah, sounds reasonable. Okay, so speaking of seven days.

[00:28:57] Daniel: That’s the best one to date.

[00:29:00] Dara: That’s the best/worst segway into the wind down. What have you done apart from self-destruct like a cookie within the last seven days when you’ve not been working.

[00:29:13] Daniel: You’ll like this Dara, actually, I went out for my first, not say first ever, but my first in a very long time, run. I’ve done one run and it went really well, so I’ve already got over eager and cocky about it and classed myself as a runner and thinking about what 10Ks and half marathons to sign up to. But I’m going to start, I’m going to make it a habit, I’m going to make it part of my routine and I’m going to run twice a week. So I though I’d let you know I’ve joined the club.

[00:29:34] Dara: Brilliant. Well, you mentioned the half marathon, so the Brighton half marathon is coming up, so you could join that. You’ve got 12 weeks.

[00:29:42] Daniel: Is that good enough? Is that enough time?

[00:29:43] Dara: It depends, how comfortable do you want to be and how well do you want to run it?

[00:29:48] Daniel: I might run twice a week, is that enough information?

[00:29:51] Dara: Mm, might be a stretch but welcome to the club. It’s great to have you on board. I joined the glasses club last week and now you joined the running club this week.

[00:30:00] Daniel: God, this is embarrassing, we’re blending together, we’re becoming the same person.

[00:30:03] Dara: And probably the only, well interesting to me, probably the only thing I’ve done in the last week is go for lots of runs but I feel like you’ve gone for the only thing I actually have, you’ve gone in and stolen it now, so what else have I done in the last week. Well I think, and I’m being a bit of a time lord here, I think by the time this episode comes out, I will have been to Ireland to see my lovely family for my last trip this year. So it’s like a pre-Christmas trip, a long weekend just to see everybody and possibly enjoy a few pints of Guinness while I’m there as well. I mean, I did enjoy a few pints of Guinness in the future, in the past when I was there.

[00:30:42] Daniel: if you keep at this rate Dara, you’re just kicking the can down the road and it’s going to catch up with you. You’re going to then run out of future things to talk about.

[00:30:49] Dara: Yeah, I know. Yeah eventually, I’m just going to have to start completely making things up.


Dara: That’s it for this week, to hear more from me and Dan on GA4 and other analytics related topics, all our previous episodes are available in our archive at measurelab.co.uk/podcast. Or you can simply use whatever app you’re using right now to listen to this, to go back and listen to previous episode.

Daniel: And if you want to suggest a topic for something me and Dara should be talking about, or if you want to suggest a guest who we should be talking to, there’s a Google Form in the show notes that you can fill out and leave us a note. Or alternatively, you can just email us at podcast@measurelab.co.uk to get in touch with us both directly.

Dara: Our theme is from Confidential, you can find a link to their music in the show notes. So on behalf of Dan and I, thanks for listening. See you next time.

Written by

Daniel is the innovation and training lead at Measurelab - he is an analytics trainer, co-host of The Measure Pod analytics podcast, and overall fanatic. He loves getting stuck into all things GA4, and most recently with exploring app analytics via Firebase by building his own Android apps.

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