Hi there, Two things come to mind: 1) Go to the networks directly and ask them about their fill rates, historically, in your target countries. 2) Once you've identified 3 that seem pretty good, ask your programmer to implement an ad cascade. S/he can probably handle this with a .plist file if you...
In my experience, CPM ads pay much less than CPC. I think that your issue with AdSense was poor optimization / ad placement. I have a client who had very low CPC with high traffic website, and was making well over $10000 per month with AdSense. Before we optimized his site, with same traffic h...