How do we measure impact in a world without third-party cookies?


The marketing world as we know it is changing: without third-party cookies and the data it captures, we explore how businesses can find opportunities in such adversity.

First created in 1994 by Lou Montulli – a 23-year-old at Netscape, the browser-du-jour – third-party cookies have dominated digital marketing throughout the 21st century. But now they’re on their way out, and leaving an information gap that could at best plateau and at worst damage the trajectory of many brands. 

Here, we take a closer look at how companies can prepare for what’s being dubbed the “Post-Cookie Apocalypse”. But first, let’s remind ourselves exactly what a third-party cookie is, and how it works. 


A cookie is a small block of data that’s placed on your device by your web browser, whenever you visit a website. First-party cookies are added by the website itself. For example, after you sign in to, it places a cookie on your device that saves you from having to sign in every time you visit a different web page.

As the name suggests, a third-party cookie is added by someone other than the website you’re visiting. For instance, imagine you visit a local news website, The first page contains a digital ad from, which sends a cookie to your device with information on where you viewed it.

Later, you visit a different website,, which also has an ad from That means you get another cookie from Buy My Stuff, with the information that you saw the ad there too. At some point, when you click on another ad, your device will send all of these cookies to Buy My Stuff – and they will  know exactly what sites you were visiting when you saw their ads.

Being able to gather this kind of information has been central to brands’ digital marketing strategies for more than two decades – but those days are now numbered.

The dying days of third-party cookies

Firefox and Safari have already phased out third-party cookies. Since May 2021, new iPhone and iPad users have been automatically opted out from them. Nowadays, iOS users are asked once – and only once – whether they would like third parties to track them (and let’s face it, it’s unlikely that many will click ‘yes’). In the US, 96% of users have opted out of app tracking.

At the same time, more and more people are using ad blockers, anti-spyware software, VPNs and browser privacy modes to prevent third-party cookies from appearing on their devices. The final nail in the coffin will come in late 2023, when Google removes third-party cookie tracking from Chrome, which accounts for more than half of global web traffic.

The end of third-party cookies is set to change everything – and marketers need their strategies to navigate  this brave new world.


Third-party cookies have shaped where digital marketing is today. Our practices, our approaches, our very ways of thinking are centred around their existence. Losing third-party cookies will force a monumental shift: brands will have to think carefully about how they manage consent, data management and privacy. Consumers will hold the power over what information they provide, and how it’s handled.

So what will all this look like in practice?

It’s difficult to say with any great certainty. While Google says it’s developing an alternative to third-party cookies, it appears to be struggling.

Back in 2021, we were promised FloC, which stands for Federated Learning of Cohorts. This involved Google generating profiles of groups of users (aka cohorts), without tracking the activity of individual users. This approach proved unpopular. It was consequently abandoned in January, superseded by a new strategy called Topics.

The idea here is that your browser determines a handful of topics, such as ‘Fitness’ or ‘Travel and Transportation’, which represent your top interests for that week based on your browsing history. Topics are only kept for three weeks, with old topics deleted.

It’s an interesting approach, but one that’s very much in development with release dates penciled in 2023. Other tech giants are also floundering to present compelling  replacements for third-party cookies. Brands can’t rely on Silicon Valley to solve this problem: they’re going to have to come up with workable solutions themselves.

A switch to first-party data

Different brands will take different approaches, but they will all have certain things in common. Firstly, rather than third-party data, we’ll all be looking closer at first-party data.

First-party cookies, for instance, are not under threat. Brands will still be able to gather data about visitors to their own websites. You’ll still be able to see the number of pages people click on, the type of browser and device used, and visitors’ geographical locations. If users arrive via a link on another website, you’ll know which one. A lot of very useful data will still be available.

The post-cookie landscape will also be a good time to dive deeper into broader datasets thrown up by your website analytics: search uplift or share of search as a whole can be used to monitor purchase intent. Elsewhere online, share of conversation and social comments can be analysed to understand brand sentiment.

Beyond that, remember that website visitors can still volunteer information about themselves if they choose – and there’s no reason why they shouldn’t. After all, while people are suspicious of technology in general, and faceless tech giants in particular, they’re much more open with brands they know and love.

Engaged customers are keen to share

Part of this is about choosing the right mechanism in the right context. For example, most of us automatically close newsletter sign-up pop-ups when we visit a site – they get in the way. Imagine a pop-up at the end of Encanto on Disney+, asking you whether you’d like to see more films like this in the future…

Clicking ‘yes’ or ‘no’ is easy. It doesn’t delay or distract from your enjoyment of the movie (it’s already finished). If you feel an emotional connection to the brand, like Disney actually cares about your opinion, you’re much more likely to answer.

You can take this principle far beyond direct interactions on your website. As the third-party cookie fades into view, it’s a great opportunity to look for new ways of researching customers and gather much deeper and richer layers of data. These may include surveys, competitions, newsletters, subscriptions, forums, user testing, market research, and customer panels. You don’t need to pursue them all, but a mixed-method approach is likely to be the most productive.

Such techniques require investment and commitment, but the potential rewards are huge. And while it’s true some of these methods have been found wanting in the past, that’s less about the method itself and more about how it has been implemented.

For instance, traditionally, many marketing departments saw it as their job to gather the maximum possible amount of information, and think about what to do with it later. In today’s world, people are time-pressed, and unwilling to divulge too many details unless it’s obvious why they are relevant. It’s vital to think carefully about what type of information is most crucial, rather than focusing on quantity.

To take one example, do you actually need to know the gender of the person providing data? Maybe, but if you’re not questioning it, you’re not thinking in the right way.

All of this boils down to understanding and empathizing with your customer – because engaged customers are keen to share. There’s no need to ‘trick’ people into giving their data, if they’re ready to do it willingly.

A return to contextual advertising?

You only get first-party data if people visit your website. So how do you get people to come in the first place? One strategy might involve a return to contextual advertising.

While third-party cookies let you deliver ads to specific kinds of people, contextual advertising instead focuses on websites that are relevant to your brand. If your company helps people to live healthy lifestyles by delivering fresh ingredients to their door, you might want to advertise on sites related to health, sports or cooking.

This isn’t rocket science: it’s a tried-and-tested approach from the days of print. But there’s plenty of evidence to show it works in the digital sphere too. It’s arguable that relying on third-party cookies over the last two decades has led to an over-dependence on private data, and a lack of innovation in targeting interests over personal profiles.

Anyone who has bought something online and been subsequently served with incessant and pointless ads for the same product, purely for visiting that site, will appreciate that third-party cookies were never the ideal solution in the first place.

The FUture?

The demise of third-party cookies is ongoing, and soon they’ll be gone forever. No brand wants to be left in data darkness, so the race is on to find alternatives. Google, Apple, Mozilla, Amazon and other tech giants are all scrambling to find tech fixes, and they may well come up trumps. But lack of progress so far suggests it would be foolish to rely on these alone.

Instead, brands should see the demise of third-party cookies less as a marketing problem, and more as a marketing opportunity. Taking a glass-half-full approach, this is a chance to go beyond big data, and find ways to gather more useful, layered, nuanced and relevant data, both online and off, while giving consumers the privacy they crave.

Brands will have to evolve, shift their mindset, approach and become less reliant on old practices. The post-cookie landscape of 2022-23 and beyond will no doubt be unpredictable, chaotic and constantly evolving. But holding fast to key principles – namely, understanding your audience and finding creative ways to engage with them – will allow you to stay nimble, flexible and able to grab at new opportunities with both hands.