In September 2022, AdSense began rendering ads via the Protected Audience API (formerly known as FLEDGE) as part of our testing. We currently run Protected Audience auctions on a limited percentage of AdSense traffic.
What is the Protected Audience API?
The Privacy Sandbox provides web technologies that preserve people’s privacy online and give companies and developers the tools to build thriving digital businesses, which keeps the web open and accessible to everyone.
One of the Privacy Sandbox proposals that is being tested in Chrome is called the Protected Audience API (formerly known as FLEDGE). The Protected Audience API proposes new privacy-preserving ways to power remarketing and custom audience solutions so advertisers can re-engage with site visitors.
With the Protected Audience API, the browser stores advertiser-defined user interest groups and hosts on-device auctions to show ads. Similar to how interest groups work today, the Protected Audience API will help marketers do things like showcase different product categories, appeal to visitors who didn’t convert, and re-engage visitors who abandoned shopping carts. Unlike today, however, companies will not be able to track individual users across the web via third-party cookies.
How AdSense serves ads with the Protected Audience API
When a user visits an advertiser’s website, the website (or an ad tech provider embedded on the website) can ask the user’s browser to associate the user with a specific interest group. The user’s browser then periodically fetches information about potential ads which could be shown to the user for each interest group, including information from advertisers.
Later, when a publisher wants to serve an ad to the user, an ad request is sent to AdSense. This request does not contain any information about the Protected Audience API interest groups. Once third-party cookies are deprecated, the request won't contain any third-party cookie data.
AdSense then runs a server-side auction to select the best non-interest group ad. Note that publisher controls apply as usual during the server-side auction. Following the server-side auction, AdSense returns the best non-interest group ad to the browser as well as information about publisher controls to apply in the on-device auction.
Finally, the browser runs an on-device auction between all interest group ad candidates and the best non-interest group ad. The winning ad is then rendered.
Opting out of the the Protected Audience API
If you want to opt out of Chrome's the Protected Audience API, use Chrome’s Permissions-Policy:
- Set
Permissions-Policy:run-ad-auction=()in the HTTP response header during the origin trial, which prevents anyone (including AdSense) from running the Protected Audience API auctions on your site. - You can also set
Permissions-Policy:join-ad-interest-group=()to prevent advertisers from adding users to interest groups on your site.
