One of Google's big new bets to save targeted advertising on the web once it kills off third-party tracking cookies in its Chrome browser just hit a major snag, after a key web standards body rejected the proposal.
The online ad industry is racing toward a 2024 deadline when Google says it intends to phase out third-party cookies from Chrome, the world's most popular web browser. Since 2020, Google has been testing a number of cookieless proposals as part of its Privacy Sandbox initiative, which are designed to allow targeted advertising to continue to work on the web but in ways that better preserve user privacy.
Once such proposal is Topics API, which allows advertisers to target ads to website visitors based on broad topics like "fitness" or "books," based on their browsing history on a given site over a three-week period. Inferred by the browser, these topics wouldn't identify the user to the advertiser or their adtech vendors. Instead, those topics would surface up to five areas of interest for that user over that period of time.
But Google might now have to go back to the drawing board. On Thursday, a division of web standards body the World Wide Web Consortium, known as the W3C, asked Google not to go ahead with Topics API in its current form.
"The proposed API appears to maintain the status quo of inappropriate surveillance on the web, and we do not want to see it proceed further," wrote Amy Guy, of the W3C's Technical Architecture Group in a Github post. The TAG is responsible for building consensus around principles for web architecture.
A Google spokesperson said while it appreciated TAG's input, it disagreed with the characterization that Topics maintains the status quo.
"Google is committed to Topics, as it is a significant privacy improvement over third-party cookies, and we're moving forward," the Google spokesperson said in a statement.
Guy and the W3C didn't immediately respond to a request for comment.
Guy said that Topics didn't give users enough control around the topics being shared from their browser and that third-parties could stitch together data from topics with other data about a user in order to build profiles on them.
Guy also raised concerns that topics could be used to customize content in a discriminatory manner. That could include the potential to select which ads to show groups of users by inferring sensitive or protected characteristics, such as a person's race.
The W3C rebuke marks the latest in a series of snags in Google's effort to kill off third-party cookies. Topics, for instance, was meant to replace another failed proposal, called FLoCs. The deadline to end third-party cookies has already been delayed twice and Google was forced to pledge in 2021 to give the UK's Competition and Markets Authority oversight of its plans to roll out alternatives in response to an investigation by the antitrust watchdog.
Third-party cookies are small files stored on a user's device that allow advertisers and adtech companies to track users as they browse various sites on the web. They allow a hotel, for example, to target ads to users who have previously visited their website — and they help advertisers measure whether their campaigns are working. However, other browsers like Apple's Safari and Mozilla's Firefox already block third-party cookies as privacy features.
Guy also noted in the Github post that the Topics proposal hadn't received support from Mozilla and Webkit, responsible for the Firefox and Safari browsers respectively.
Robin Berjon, standards and governance lead at research firm Protocol Labs and a W3C board member, said the latest development from TAG suggests Topics API has little chance of a credible future.
"No other browser vendor wants it, and the leading authority on web architecture has rejected it," said Berjon.
Despite the rebuke from the W3C, Google could still opt to follow its own path, not least as web standards can take years to thrash out and it isn't bound by them. The company has its own commercial priorities and the commitment to the CMA that it can't remove third-party cookies until new features provide an adequate replacement. Topics is particularly important to Google to this end because it is relatively easy to implement and test, said Alex Cone, cofounder of ads privacy learning platform Coir.
"If they find that it provides value to advertisers they're going to do it," Cone said.
Testing of Google's Privacy Sandbox proposals has also been slow to get off the ground. Publishers have previously expressed concerns that Topics would give ad tech vendors the upper hand because they'd be allowed to access more data from publishers than the publishers themselves.
