Rather than the browser sending a summary of your history, it calculates a cohort ID. That ID is sent to websites, and the website then has the job of associating IDs with interests.
So instead of building a profile on specific users, the website (or ad network) builds profiles on cohort IDs. Users can change IDs, or mask theirs altogether if they wish.
So instead of building a profile on specific users, the website (or ad network) builds profiles on cohort IDs. Users can change IDs, or mask theirs altogether if they wish.