That is murky. I have real time nosql (hadoop) tracking on
ads billed as served CPM and the ability to track actual CTR by the person who is referred by IP.
I can see what ads create CTR; from what advertiser page; and what pages on our sites are viewed -- right down to the individual model and sometimes the duration.
If I have the time or the inclination to do so
We have other people doing this as part of their full time jobs.