Over a year ago I wrote about the fourth arbitrage: retargeting traffic and probably did not do justice to the topic.
This video from Iponweb CEO, Boris Mouzykantskii, was filmed at the recent ATS London, is in the same sort of area, and is certainly worth a watch.
Yes, this conference has Display in mind. This is the "new" kind of display, though, the programmatic type that speaks to my search heritage and in the same language as my affiliate marketing history. It might well be the same for you.
In short, this video should intereset anyone in the bought media space; certainly the biddable media space (which includes PPC).