Comparison Google and Appstore

Question to developers having apps on Google and Appstore. What is the difference of downloads of the same application on the appstore and google?

One of my apps exist in identical versions on ios, android, windows 8 store (both phone and RT). It’s a paid niche app with very little competition. Revenue looks like something like this:
75% appstore
20% google play
5% windows store

I did this as an experiment (which paid off ok as well). I’m now focusing on Android (haven’t done an iPhone app in ages) and are currently doing free apps with ads. I’m not very fond of Apple but revenue does seems to be a lot better for paid apps on that platform.

Google Play - 2000 downloads per day right now (it’s an old app)
AppStore - 50 downloads per day on the same app.

It had up to 30k per day on Google when I released it, only 200 on iOS and it dropped to 50 after Christmas.
Paid version of this app paid for the iOS fee and iPad Mini I had to buy and then dropped to almost zero.

Of course on Apple I don’t have cross-promoting power because it’t the first time I’ve released there.

For now though I think it is better to release only paid apps on iOS or apps with IAP.