When I worked in RTB (about 10 years ago), the profile information sent as part of the bid request was really quite low granularity and very anonymized. There w

When I worked in RTB (about 10 years ago), the profile information sent as part of the bid request was really quite low granularity and very anonymized. There wasn't a lot there, just fairly broad demographics. With cookie matching and third party data services, you could in theory extend this. But obfuscation of tracking cookies and so on was enforced by the bigger parties like Google AdX, etc. so that it wasn't usually all that feasible. Has this changed significantly? The various cookie matching and data markets out there are more disturbing to me than RTB itself?