This is something that I've been interested in for awhile. I tried to set up a system that would target ads to users based on the information that I had in my own database instead of what was on a specific page. If your pages require a user to be logged in then the google bot can't access that data, so you get poor ads. It would be great if I could scan the data internally, then send a keyword request to Google, or whomever, and get back ads based on the information I sent. That way I can keep my users data private while still providing them high quality targeted ads. Does anyone know of an ad company that allows that?
Dunno but I think your on to something here. Only one way to find out if your idea works though...