Google Chrome Will Drop Third-Party Cookies In 2 Years

Third-party cookies – the backbone of programmatic advertising – are not long for this world. Google’s Chrome browser will phase them out in two years, according to a Tuesday blog post.

Google Chrome is betting that its Privacy Sandbox – the privacy-preserving API first unveiled in August – will over the next two years build functionality that replaces third-party cookies.

“We are confident … mechanisms like the Privacy Sandbox can sustain a healthy, ad-supported web in a way that will render third-party cookies obsolete,” said Justin Schuh, director of Chrome engineering.

Google Chrome proposes to store individual user-level information in the browser, letting outside ad tech companies do an API call to the Privacy Sandbox in order to receive personalization and measurement data without user-level information.

The idea bears some similarity to Ads Data Hub (ADH), a Google spokesperson said. Since Google closed off access to DoubleClick IDs, the only way to analyze user-level information in campaigns is through Google’s privacy-focused ADH cloud. And the data can’t be exported.

How Google will support cookie-less measurement and targeting

The loss of third-party cookies endangers a number of marketing activities on Chrome, from targeting to measurement.

Google’s Privacy Sandbox will first try to solve for conversion measurement, followed by interest-based advertising.

By the end of this year, the Google Chrome team will begin trials that allow for click-based conversion measurement without third-party cookies. Conversions will be tracked within the browser, not a third-party cookie, according to a Google spokesperson. When an advertiser needs to track a conversion, they’ll call an API  that will send the conversion value from the browser. Individual user data would not be passed back.

Google Chrome will next explore how to run interest-based advertising without third-party cookies.

This pilot will test a couple of different scenarios without third-party cookies.

For instance, an ad tech provider might call Chrome for a list of people who have visited a group of 100 sites, avoiding granular targeting. Or, Chrome might group people with similar browsing habits.

Regardless of the methodology, it seems as if Chrome will support messaging a cohort of users, but 1:1 messaging is out.

Massive impact on Google, publishers and vendors

These changes will affect Google’s business buying ads across the open web, often known as its DoubleClick business, a Google spokesperson confirmed.

Google Display Network, for example, relies on third-party cookies to serve ads based on a person’s browsing behavior. For those ads to continue running, this Google product would need to use the Privacy Sandbox API.

And Google’s partners – including publishers using Google Ad Manager to sell their ads – would likewise be affected. Google released a study last year showing that removing third-party cookies reduced publisher ad revenue by 52%. Making sure this change doesn’t negatively impact publishers is a priority, the Google spokesperson said. The upcoming pilots will compare monetization for publishers under the new setup vs. the old one with third-party cookies in place.

However, Google’s much larger business serving ads on and would mostly be unaffected, since it runs on first-party cookies.

Chrome’s Privacy Sandbox is open, and any ad tech company with a third-party cookie offering would be able to call the API.

However, these outside ad tech providers would lose access to data they gathered through third-party cookies when they get phased out. Instead, they would need to target and measure ads by calling the Chrome browser API.

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  1. The future is cookieless (not just first vs. third party). Building systems, agnostic to Chrome, Safari, Firefox, and the rest will be the required result. While Googles Privacy Sandbox seems great in theory, it seems like it will only stimulate users further into the browser wars. Interested to see how this one plays out!

  2. Rob Armstrong

    The original Chromium blog post emphasizes industry collaboration through the w3c “Improving Web Advertising” working group – yet this group contains only 5 independent adtech members, while having 20 individuals from Google and Facebook alone.

    And we are to trust that outcomes from w3c will not benefit walled gardens at the expense of independents?

  3. Um, DMPs out of business 100%. However, I am curious how DSPs will react to this and will it be efficient enough for them to go back to contextual segmentation and finally using Unified IDs?

  4. Since the demise of the “Ask Me Every Time” cookie privacy feature once available through Firefox, Water Fox and Pale Moon browsers (due to pressure from advertisers?), privacy has been harder to attain.

    If cookie- third party and otherwise- are ever on the way out, rest assured the specifics of what is now being planned to replace them will be far more intrusive and harder to avoid, delete or render ineffective.