Anyway, yes I replied to the "where users go", and not to the "where users pay" thing, because I think it is two problems.
So apparently, by the numbers, users go Android, but iOS users are currently more willing to purchase apps, right? Maybe. But not sure. I don't think Android users would be that reluctant to pay a small amount of dollars for an app they really want, if it were convenient.
I paid happily for Minecraft, Machinarium, GTA and 4/5 utilities. The problem is probably that the main source of data, the Google play market, is currently not open to transactions in China and maybe other big countries. So, for me, to buy an app I need: a rooted device, the "fake US location" app (market enabler), a working VPN installed on the phone, and a credit card.
I would like to know the numbers for local Chinese markets, but given that they try very hard to attract user it should probably be juicy, or at least very promising.