Not that the PPC engines currently give you anything other than keywords as a way to get qualified traffic, but if they did allow advertisers to bid by the additional axes of behavioral and demographic user data, what do you think those additional targeting capabilities would do for advertiser ROI from paid search?
A) Would smart advertisers get higher ROI at others' expense?
B) Would additional, net new buying intent be uncovered by such targeting such that paid search traffic overall would become more valuable?
C) Would ROI stay the same?
