PhoneGap compiles terrible slow apps and allow only 1 app for free. Comparing to CocoonJS it really, really sucks. So it's not solution.
I was messaging Ashley on this topic and I repeat again: there should be some NATIVE support for banner and full screen interstitials in C2. Let Scirra make deal with some ad network, take 10% of traffic, but DO SOMETHING.
If C2 is professional tool, then it should have serious monetization methods too.