[lionheart]

It's not necessarily quite that bad. The list can be made modular.

One option would be to start of with a list of the top 500 sites and then determine from that information what demographic the user fits it. Then you could load a list of sites pertaining to that demographic and further narrow down the user's behavior.

Also, if you're talking about ads on a certain site, the publisher can make a list of the sites in their niche and then you could load that list and move on from there.

All in all, this has some very interesting potential. The question is, why hasn't Google done it already?

[breck]

They have. I'm pretty sure Doubleclick does this. Without the CSS hack though(using the cookie method).

The CSS hack is only worthwhile if you don't have the kind of data sources that the big guys have. If this technique actually made money, you would probably want to sign up for something like Lookery or RightMedia because they'd get you better results.

[jjfarren-]

If you read carefully on our website you will learn about the limitations of cookie based methods.