Ad tech firms test ways to connect Google’s FLoC to other data
The FLoC ID assigned to people is updated weekly, which is meant to filter them into gradually evolving collectives and seemingly limit a FLoC ID's use as a persistent identifier. "If your behavior doesn't change, the algorithm will keep assigning you in that same cohort, so some users will have a persistent FLoC ID associated with them - or could." He and other people interviewed for this article stressed that because Google is testing FLoC on a very small portion of web traffic during the trial period, there are limits to how they can use the data today and to the statistical significance of their analysis. While the company has yet to incorporate FLoC IDs as a consistent data source, Roche said a FLoC ID could give the company's system an accuracy boost. Because a FLoC ID represents a relatively small number of people - a thousand or so rather than hundreds of thousands or millions - FLoC IDs would essentially reduce the number of vectors necessary for the firm's identity method to work because the system could determine that someone had been assigned that particular ID before. Neustar is gathering FLoC data from its own site activity and testing what's coming in from FLoC trials on website traffic from some clients' sites, said Devon DeBlasio, product marketing director for the firm, which helps brands manage and use data and offers identity technology. "We can use FLoC data not just for placing ads to the subset of the audience that has FLoC, but also to inform contextual placements for users who don't have FLoC - whether because their browser doesn't support it, they have it turned off, or their cohort is blocked," said Marti. Clearly, other companies do see FLoC IDs as potentially valuable identity data, which is why privacy researchers like Cyphers see them as a not-so-theoretical privacy problem.