They are willing to do that: It's a large reason they acquired DoubleClick. But yes, this is one of the more promising areas of development for ad serving compa

They are willing to do that: It's a large reason they acquired DoubleClick. But yes, this is one of the more promising areas of development for ad serving companies, privacy concerns aside. I recently moderated a panel where the panelists explain that, without anything but an IP address, they could tell if a reader had browsed a car site, a new parenting site, etc. and then target ads on a completely unrelated website with that info.