GroupM, WPP’s media investment arm, is lending its weight to push ad tech providers to experiment in Google’s post-cookie platform, announcing that it is working with its brands and Google Chrome to prepare for the coming shift in digital advertising. GroupM launched today what it called a “readiness program,” in partnership with Google Chrome, to understand how the ad tech ecosystem will evolve once cookies sunset next year.

“There is demand there for tests,” Richard Mooney, GroupM’s Privacy Sandbox workstream lead, said in an interview with Ad Age this week. “Advertisers are keen to make sure we hit the ground running. Therefore, we urge ad tech providers to listen and to come to the table and take advantage of that interest from advertisers.”

GroupM has already been testing parts of Google’s Privacy Sandbox, which is a series of APIs—application programming interfaces—designed to run ad auctions, deliver ads and measure their effectiveness without relying on cookies that track consumers. But the true tests won’t start until January, when Google’s Chrome web browser turns off 1% of internet traffic to cookies.

Google has said it expects to turn off 100% of third-party cookies by the end of next year. Many ad tech providers are working on alternative identity solutions, and they are building up first-party data products that attempt to address privacy concerns.

However, Chrome’s cookie deprecation will undoubtedly be felt by advertisers, which is why testing Google’s new protocols is a priority, Mooney said.

Educating advertisers on the changes

“The ad tech ecosystem, those products that our clients interact with day to day, are in some way supported by third-party cookies today,” Mooney said. “Therefore, those solutions are at risk and that’s something we’ve been really making sure that our clients really understand.”

“The ad tech ecosystem as it stands is more underpinned by third-party cookies than perhaps is visible to a lot of advertisers and marketers out there,” Mooney added.

GroupM’s announcement was partly to ensure that advertisers have a seat at the table as ad tech partners make post-cookie modifications, Mooney said. “The advertisers want to know what impact [there will be],” he said. “They want us to allow them to gain greater transparency over the changes the ad tech providers are making and to work with the ad tech providers through this partnership and program.”

Cookies have been seeping out of programmatic advertising for years, especially since Apple started blocking third-party cookies in Safari in 2017. Apple has since made similar anti-tracking changes on iPhones with rules that prevent apps from tracking consumers without their consent. Google is following a similar roadmap just at a slower pace. Google plays such a large role in internet advertising and any changes it makes could hobble rivals that rely on the open web to conduct business.

Some ad tech providers and publishers are concerned that Google could limit the availability of data while advantaging its own business. Google’s Chrome team has been spearheading cookie deprecation, separate from Google’s ads team. Some ad tech providers have been slow to test Privacy Sandbox, or prepare for it fully, in part because the program has faced delays in the past, but also rewiring programmatic ad pipes can be expensive and drain resources.

Google is rolling out Privacy Sandbox while being watched by the U.K.’s Competition and Markets Authority. The regulator wants to ensure that data changes to Chrome don’t stymie Google rivals and businesses that rely on a well-functioning internet. A Google spokesperson said that the work with GroupM is focused on getting real-world tests in the first quarter of 2024 and providing feedback to CMA.

“Transitioning to new technologies takes time,” the Google spokesperson said in an emailed statement. “We believe this program, led by WPP, will enable advertisers to test the integration of privacy-preserving technologies on live campaigns ahead of third-party cookie deprecation.”

GroupM’s call to prepare for Privacy Sandbox could mobilize more ad tech players.

“This is where the rubber meets the road, right,” Mooney said. “This is where we have a big opportunity in front of us to balance consumer privacy and marketing effectiveness, and it requires us all to lean in and test them in the real world in an end-to-end fashion.”

Advertisers want to test Google’s new APIs, alongside other products in the ad tech industry, including other advertising IDs and first-party data, Mooney said. In that way, GroupM’s tests are not just relying on Google’s Privacy Sandbox. “Google is not stating that the privacy APIs should be used in isolation,” Mooney said. “So what we will see next year is ad tech providers using these signals alongside other signals to develop ad solutions and products.”