Third-Party Cookies: The Great Comeback (or Not)? Why First-Party Data Remains More Essential Than Ever

Published on

6 May 2025
NewsMarket updates

Five years of announcements, U-turns, promises, and prototypes… only to end up back at square one. That’s how many in the adtech industry felt-unsurprised-when Google announced yet another delay in phasing out third-party cookies 🍪 in Chrome.

But make no mistake: this does not change the direction the market is heading. The consensus among adtech and advertising experts is clear: third-party cookies are neither viable nor sustainable, and certainly not privacy compliant 🔒. The only certainty emerging from this technological and regulatory fog is that first-party data is-and will remain-the strategic compass for brands!


1. Third-Party Cookies: A Mirage Fading Away, Slowly but Surely 🍪

Even with their temporary reprieve in Chrome, third-party cookies are already in decline and:

  • 🚫 Not compatible with regulatory and ethical expectations: As Thomas Adhumeau notes, “this is no longer a privacy strategy, it’s an admission of powerlessness.”

  • ⚠️ Technically limited: Unable to work cross-device, blocked on Safari and Firefox (over 40% of global traffic), third-party cookies have become an “obsolete vehicle,” as Jean-Baptiste Rouet points out. A vehicle incapable of targeting, retargeting, controlling, or measuring-leaving agencies and brands blind to the profitability of their investments.

  • 🌐 Incapable of addressing web fragmentation: As Agence 79 states, their “reliability and coverage” are too low for modern media strategies.

In short: “We’re not going back to a world driven by third-party cookies,” says Thomas Allemand.


2. Deterministic First-Party Identifiers: The Pillar of Performance and Sovereignty 🔑

As cookies lose steam, other solutions have emerged-and brands that anticipated this shift by investing in first-party data alternatives have taken the lead. As Paul Ripart notes, “This period spurred innovation, encouraging the development of addressability solutions.” Baptiste Percherey even calls it “an opportunity to pave the way for a more balanced ecosystem that allows for healthy competition.”

Why is this data key?

  • 🌍 It can be activated everywhere (logged-in or not, retail or media environments…)
  • 🔄 Works independently of browsers or platforms
  • GDPR compliant, as it is collected with user consent
  • 📊 Enables precise targeting and reliable measurement, often outperforming cookies

That’s why it’s vital to build proprietary strategies, centered on your b, and adaptable to every environment.

This is essential for:

  • 📰 Publishers: to “build more direct and lasting relationships” with their audiences, as Àlex Rodríguez highlights
  • 💻 Tech providers: to “work with cookies, IDs, and contextual signals… We’ll be able to rebuild ambitious strategies and give more weight to the open web,” as Alain Lévy reminds us
  • 📈 Advertisers: to “test, seek out, and adopt alternatives,” as recommended by Havas Media Network

3. An Unstable Ecosystem Calling for Independence 🏛️

Between regulatory setbacks and technological failures, the Privacy Sandbox initiative has crystallized tensions around Google’s advertising monopoly.

Google’s recent announcement is not a step backward. On the contrary, it confirms the need to break free from a hegemonic and unstable system:

  • Privacy Sandbox remains a black box, little adopted, with complex APIs and rarely realized promises.

“It’s a fiasco that has absorbed the industry’s attention for five years,” says Alain Lévy. “Thousands of hours and millions spent, anticipating a revolution… that never came.”

  • Google’s ecosystem is under regulatory pressure: fined for abuse of dominant position, the future of Chrome (and its ad business) is itself uncertain.
  • The climate is one of reshuffling: Apple, 📱 Meta, 🌐 Google… all are in regulators’ sights. The dominance of walled gardens could falter, increasing uncertainty and opening the door to a more open, independent web.

4. Toward a “Half-Cookieless World”: Adapt, Test, Master Your Data

As Florent Couton points out, the market is already more than 50% cookieless, and nothing suggests this trend will reverse. Keeping cookies in Chrome does not solve the addressability or performance problem.

“Less data, less reach, less performance” sums up Alban Pelletier.

The real priority for brands? Regain control over their data, structure hybrid omnichannel strategies, and invest in cross-platform measurement solutions, as Brian O’Kelley highlights.


5. Conclusion: The Only Data That Matters… Is Your Own

Don’t depend on third-party cookies. Don’t depend on a single platform. Don’t be subject to the instability of an obsolete system.

That’s the message the entire market is sending today. Third-party cookies may not disappear immediately, but they are no longer the foundation of modern advertising.

First-party data remains the key to thriving in a world with or without third-party cookies, regardless of Google’s timeline!

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