FLEDGE: User-based A/B testing

[alois-bissuel]

Hello,

A/B testing is at the heart of the web and its constant improvement. It applies to ad tech in particular. In its current form, FLEDGE does not allow for owner-wide AB-testing.

Following the idea laid out in SPARROW, we would like to propose an identifier to be added to the browser signals (for bidding and reporting).
This identifier would be specific to the IG owner, resettable by the user at any time (and might be periodically reset by the browser), and be of very low cardinality (say less than 32).
This would enable buyers (and sellers too, if they set their identifier) to run a handful of A/B tests simultaneously (depending on the split) while presenting a very limited risk for privacy.

What are your thoughts on this?