Cohort audiences are Google’s solution for how ad targeting can work in Chrome without third-party cookies. Cohorts are groups of consumers with the same interests, based on their browsing behaviors. They are meant to be large enough groups so that individuals remain anonymous, using common interests in place of individual identifiers.
Google has two proposals called FLoC and FLEDGE for advertising without cookies in Chrome, both involving interest-based cohort audiences. Criteo also introduced a proposal called SPARROW, some elements of which have been incorporated into FLEDGE. SPARROW aims to enhance Google’s proposal by providing more control and transparency while maintaining privacy guarantees for users. These enhancements include:
- Audience discovery and extension: In addition to driving traffic and sales through engaging users based off the interest group they belong to, SPARROW would allow advertisers to create upper-funnel and lookalike campaigns based on those interest groups. These campaigns typically aim at bringing new products and services to the attention of users, and SPARROW proposes a design that makes these strategies possible in a cohort-based privacy approach.
- Data protection and security: In the SPARROW proposal, Criteo recommends having an independent party, or gatekeeper, execute real-time bidding rather than the browser doing so. The gatekeeper protects user group data by ensuring that advertisers, publishers, and AdTech partners cannot access any personal information about users’ interests and browsing behaviors.