At our local Android developer's meet-up, we had a local game developer who has released several paid and ad-supported games. There are two relevant observations he made:

1. He often made more money from the ad-supported free versions of his games rather than the paid versions.

2. The Play Store is not the only place to download/pay for Android games. According to him, there are hundreds of alternative markets (such as Amazon's), some of which are much more prevalent outside the U.S.