I think what you want is ad serving technology. For most ad networks, the technology for serving ads is their secret sauce, because after that it's about having

I think what you want is ad serving technology. For most ad networks, the technology for serving ads is their secret sauce, because after that it's about having sales people contact advertisers and publishers. Try to shop around different ad servers first and get a bunch of demos. OpenX, Zedo, AdJuggler are all decent for someone just starting out. Then, as you find it is indeed a viable business for you, then you can take your experiences with existing ad serving technology and build your own custom one.