This is a classical example of a Prisoner's Dilemma [0] The conclusions drawn by the author don't seem to consider the fact that if Ebay doesn't buy ads next to it's own name, Amazon would. As with a Prisoner's Dilemma situation, if all parties(In this case companies with substantial recognition and brand loyalty) stop buying ads, they would stand to make the maximum profit. However, this opens them up to the possibility of losing clicks to a 'cheating' competitor, thus driving them into essentially an 'ad war'. [0] http://en.wikipedia.org/wiki/Prisoner's_dilemma#In_economics