what tools available for on-the-fly decisions over ad display

Right. Assume no great advert syndications hence no cookies can be processed.
Say, you want to do poker-related and casino adverts. in order to maximise CPA effectiveness, you want to TARGET / PROFILE your random visitor and select the best advert to show to them.
for a completely fictional example. you have referral bonuses for the following sites:
PokerStars.com
PartyPoker.com
888.com
Poker.com
VictorChandler.com
fulltiltpoker.com
skypoker.com
williamhillpoker.com
are you able to determine if your visitor has already been to any of these sites? the logic being, show them an advert / banner for one they have not visited yet.
by the same token, if they have visited none of these sites, chances are they don’t much care about poker anyway – but we can then check in the same way if porn ads will work better instead? or if computer hardware gadgets are of interest….
you get the idea anyway – so what such tools/services are there?

See original post by dimitar christoff