This may be old news, but I have noticed that IE and Opera do not display the same ads. Opera serves considerably more PSA's. Any reason for this?
europeforvisitors
12:20 am on Oct 9, 2003 (gmt 0)
Dunno about the PSAs, but I see different ad combinations on some of my pages every time I click the reload button. Could it be that Google rotates ads with identical bids and clickthrough rates?
