Okay, one more hint, I know I will get more competition but well, go for Bing traffic, as mentioned above, Bing users use IE, they are in most cases noobs, they convert, you will see no smart pricing, high CTR. Bing is underrated, stop being a Google lemming.
Do you remember the old AOL times? This was the best traffic, they converted 1:10. I really hope Bing will reveal some sort of Adsense some day. Bill G. where are you? Bing we really need an adsense clone, come on guys.