This experiment exposes a temporary set of APIs which provide access to browser-determined treatment and control groups to support opt-in server side testing of the third-party cookie deprecation.
To prepare for third-party cookie deprecation, it is important to understand the full impact of Chrome’s planned transition from third-party cookies to the Privacy Sandbox Ads APIs. One important step is to support opt-in server side testing by ad techs, which can examine how systems perform if cookies were not to be used. Given the large number of ad techs involved in these systems, for example in a Protected Audiences auction, the browser is in a unique position to support consistent experimentation across all of these parties. Browser-determined control and treatment groups would allow all of these parties to run experiments involving traffic from consistent groups of users, allowing meaningful comparison and experimentation of cookie deprecation.
Explainers: https://github.com/privacysandbox/tpcd-labeling/blob/main/cookie_deprecation_labeling_explainer.md https://developer.chrome.com/en/docs/privacy-sandbox/chrome-testing