The issue with metrics like these is that they are ultimately useless. Revenues are going to depend upon the developers as much as the user. A developer has to ask themselves questions like: can they develop a compelling product and are they able to get their product out to consumers? It doesn't matter which platform you're developing for, you're not going to be able to make money unless they can answer both questions to the affirmative.

For advertisers, the situation is somewhat different, since their objective is to translate eyeballs into sales. It wouldn't surprise me if that's easier to do on iOS. Those users already fell for marketing hook, line, and sinker so what's to prevent them from falling for marketing again. (Sorry, couldn't resist the jab. ) More seriously though: there are a lot of low end Androids out there for people who have low end wallets, or who aren't interested in spending for or through their device. Yet that doesn't mean that those people don't exist, since a lot of Android users will fit into the same demographic as iOS users. It simply means that advertisers have to select their targets more carefully.