Android revenue is 5% of iOS revenue.
Android revenue is 5% of iOS revenue.
There has been a significant amount of growth in the Android sales over the last 3-4 months where it grew from around 20% to where it is now.
2) Do you have any data on paid versus free/ad-supported apps?
2) What kind of data? Data for his app? OP says he _sells_ on both platforms. Some of us may not like the idea of ads on our apps (somewhat like some of us don't like ads on our personal sites). But you may be correct in suggesting ads work better on Android than paid apps.
If you want to deduce something from an anecdote like this, these details are absolutely critical. Otherwise you can't distinguish between the performance difference being due to something random (maybe app got featured in one of the stores, causing a positive feedback cycle via the charts), something specific to the app (maybe the app was ported badly to one of the platforms), or something that applies to a wide range of similar apps (maybe the users on one platform just never buy anything).
If you find out that the app is #10 on the relevant list in one store and #1000 on the other, one of the first two options seems a lot more likely than the third one. If it has great ratings in one store and mediocre ones in the other, that's rather suggestive of the second option, etc.
You say that for the OP only the amount of money he's making matters. Maybe that's true for this single app, but it's not true when making the platform choice any future apps. For those decisions, it's critical to have more understanding of why the app performed badly on Android.