Do you still go with the big names like Facebook, Bing, and Google or do you experiment with other companies promising way cheaper traffic? Myself, I am cynical about those cheaper deals, however, I have thought about using Winterplay Studios. Anyway, the problem with "other companies", not to be a snob, is that I can't trust the source of the traffic. I mean, is it bots? Is it pop-unders sort of thrown at an uninterested audience?