You could also use another kind of advertisment. For example, Tappx uses a kind of "ad networks waterfall" and that way you lose less traffic. They work with several ad networks and your "traffic" moves from one net to another until there aren't more nets (sorry for the lame explanation, it's a brief resume of what I understood when they told me about it) But yeah, it works great! They also work with cross promotion, they gave me some advice for my marketing campaigns,so I am pretty happy with them. Just a suggestion