Finding relevant flocks for a given intent, ensuring a level playing field

[lbdvt]

Hi,

As mentioned in #27:

If an advertiser wants to target "/Food & Dining/Coffee Shop Regulars", then an ad buying platform will need to have some way of deciding which flocks are good enough matches for that intent.

For most ad buying platforms, this shall be done by looking at users' FLoC ids on various websites, or performing trials on which FLoC ids bring the best performance for that task. Observing web traffic can only be done on a subset of sites, and exploring FLoC ids space is potentially a huge endeavor, so results are likely to be sub-optimal and delayed wrt to any change.

I'm probably stating the obvious, but is it fair to say that Google, as an ad buying platform and to decide which flocks are good enough matches for an intent, will use the same methods available to other ATP, and will not benefit from having access to the FLoC source data (through Chrome browsing history sync) and FLoC clustering algorithm?

[jdelhommeau]

Very interesting point. On top of Google as ad buying platform not benefiting from the FLOC source data as mentionned in above post, will Google as an ad platform use its publisher first party data (which is enormeous compared to any other ad tech / publisher) to train its FLOC model and therefore have much better accuracy of a FLOC meaning than anyone else in the market (adtech as well as publishers).

To clarify further, one of the risk raised in the FLOC proposal is this one:

Sites that know a person’s PII (e.g., when people sign in using their email address) could record and reveal their cohort. This means that information about an individual's interests may eventually become public. This is not ideal, but still better than today’s situation in which PII can be joined to exact browsing history obtained via third-party cookies

Will Google himself exploit that risk, using his own knwoledge of a person's PII to determine with accuracy a FLOC meaning, much better than anyone else would be able to? If so, wouldn't that arguably be much more privacy invasive than current system, since Google would now be able to accurately segment users that don't use its first party, which they can't today?