The big difference between Apple and Android ecosystems that everybody spoke about at the beginning was that Apple users were willing to pay for apps and Android users were (in the beginning at least) less likely to pay up.

So here's the question for MS. Are your users willing to pay? The OP put up a graph about in-app purchases with no scale on the y-axis. To me that implies that there's no real money to show us yet. But I'm happy to be disproved.