Ad Tech measurement companies can absolutely attribute purchase behavior back to a specific individual. Having worked in this space, banks sell data with an "an

Ad Tech measurement companies can absolutely attribute purchase behavior back to a specific individual. Having worked in this space, banks sell data with an "anonymous" ID that's correlated back to an identity graph provided by a company like LiveRamp. Usually this is then used to determine whether a specific individual who viewed a advertisement (as determined by probabalistic (ip address, session id, or similar) or deterministic data (device id, account login) about an individual) has actually been "converted" to make a purchase. These data sets are not "deidentified" or "anonymized" as many of them claim, and "data clean rooms" advertised by many ad tech vendors are a good privacy aid, but are not nearly sufficient to protect vulnerable populations.