New data from App Annie shows that revenue from apps downloaded via the Google Play store more than doubled between the first quarters of 2013 and 2014 – and that a staggering 98 percent of it comes from in-app purchases in apps that were free to download.

Games continue to dominate the charts, accounting for 40 percent of all downloads but 90 percent of revenues, up from 80 percent last year … 

The Verge reports that Japan continues to be the biggest spender, with the U.S. taking second spot.

Google added Paypal support to the Play store last month, as well as rolling out carrier billing and gift cards to new countries. It also launched a mobile web version of the store, making it far easier to use on a smartphone screen.

Google is ahead of Apple in terms of app downloads, and has been slowly reducing the revenue gap.