Cookieless Future: How are third-party cookies being replaced? | Articles


“How can I continue advertising in a third-party cookieless world?”. As you know, we are approaching the end of the third-party cookies era. This will have a massive impact on Semetis as an advertising agency but of course also on all advertisers doing digital campaigns.
That’s why, at Semetis, we help our clients by advising them on concrete alternatives to provide solutions to this massive change that will impact all of our clients.

We aim to better understand what is causing these changes but also the alternatives that can already be activated and the ones that are planned in the near or long term future.

In this article, I’ll summarize the main points of Semetis’ vision about the cookieless future. Of course, it is based on solutions that are available to us in the near future and can evolve beyond.

A brief recap of the situation

Before going deeper into the concrete alternatives to the disappearing of the third-party cookies, I can only recommend that you have a look at my colleague’s article that explains what are third-party cookies (by also comparing them to first-party cookies) and what are the uses of those cookies.

But what was the original trigger to this shake-out that will deeply change the way we reach out to users as advertisers and media agencies?

Well, we consider that 3 main factors played a role here: the people, the technology and the legal aspect. In fact, higher user expectations for ads privacy are the trigger that is driving both additional privacy regulations and technology changes.

While technology providers such as Apple saw a unique opportunity to position themselves as the safekeeper of users' privacy by deploying ITP or ATT to their users, it is indeed users that initiated this change. Following these new expectations, the law followed suit by deploying GDPR and e-privacy law to request consent to be tracked in a third-party way by cookies. 

What are the alternatives?

We classified the main alternatives to the third-party in two dimensions: the solutions to build and activate reliable audiences and the solutions that will help us to keep our measurement as accurate as possible. Those two dimensions are in the core of our day to day job as digital marketers and alternatives to third-party cookies exist!

Audience Solutions

First-party Data

We know that first-party audiences will rise in importance in the future as they won’t be impacted by the disappearance of the third-party cookies.
Basing your targeting on data that you produce and own (such as customers lists) is one of the easiest ways to be ready for the cookieless future. Indeed, a transition to a first-party strategy is a must for all advertisers as first-party data moves control away from the various technology companies towards the brands which is a very healthy development.

Our take: We think that the best solutions that will make the most out of first-party data today will be done through lookalikes audiences building and by leveraging Customer Data Platforms and Data Clean Rooms.

ID vs ID free solutions

With third-party cookies becoming less and less available, there’s a need to look for other ways to identify users across websites and other devices like mobile and CTV. Several identity solutions have entered the market in recent years, including Universal ID solutions & ID graphs.

These solutions could potentially replace the utility of cookies but they are still uncertain because of the attitude that the regulators will take and the perception of the consumers.

Our take: Universal IDs and ID graphs are aimed to replace the current identifiers to help advertisers for targeting/retargeting, attribution, frequency capping, reporting, etc. On the one hand, these solutions seem to represent a viable workaround to third-party cookies. On the other hand they are not easily activable in the short term (lot of resources needed to put it in place) which is not the case of the ID free solutions such as Topics API and Contextual targeting but we then lose a bit of relevance in the audience building.

Measurement Solutions

First-party Data

Tag manager, such as GTM, is also being impacted by the cookieless world. While we previously let Google write cookies on a domain that we manage (making it the third-party cookie), we now can use server-side GTM that will allow us to leverage first-party cookies as we own the server behind GTM that will write those cookies.

Our take: While in the past, only third-party cookies were blocked by technology (ITP), today also first-party cookies can be capped in lifetime by Apple’s ITP, so server-side Tagging is not the solution to becoming cookieless proof. It can still bypass ad blockers for now which is a plus. Server-side should rather be deployed for its compliance and data governance instead


In a cookieless world with less and less data that we’ll be able to leverage, conversion modeling will be more and more crucial to be able to measure the actual performance of our campaigns.

Conversion modeling refers to the use of machine learning to quantify the impact of unobservable conversions. If no modeling techniques were employed, this attribution problem would leave holes in the customer journey, prohibiting advertisers from fully understanding the customer journeys.
These techniques use aggregated and anonymized data to estimate conversions that advertising platforms are unable to observe directly.
Our take: Solutions such as Consent Mode, Enhanced Conversion or media mix modeling are all based on conversion modeling and even GA4 is partially based on conversion modeling as well. Those solutions will greatly gain in importance in the future as we’ll need to rely on less data we can trust while extrapolation will have to be made. That’s where conversion modeling steps in.


The time to act is now!

As we saw, the cookieless world will have a tremendous impact on how we build audiences and measure performance of our campaigns.

But solutions exist to limit this impact and make the best out of it. Of course, some of them are already available while a lot are still in their early phase and not always available for testing.
As a reminder, this article is based on the solutions that are available to us in the near future. We could see completely new solutions appearing that would be able to tackle the loss of data caused by the disappearing of third-party cookies.
It is however clear that anticipating now on the cookieless future is your only option to stay on top of your results and performances!

publication auteur Alexandre Vanhemelryck
Alexandre Vanhemelryck

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