During day three of its I/O developers conference on Friday, Google announced that in-app revenues via the Google Play store are up 700 percent since the same period last year. The company’s recently launched Google Subscriptions model is also seeing progress, doubling inbound revenue each quarter since its launch about 12 months ago. Some apps using Subscriptions as their revenue model, such as Pandora, have reached the top grossing list.

“The momentum is still clearly behind in-app purchase, and as a result Google suggested that there’s good reason to consider that as a revenue model when building apps,” reports Engadget.

“Other key trends identified include a higher propensity to buy things on tablets vs. phones,” notes the article. “Google framed this in light of its attempts to get developers to build tablet-optimized experience, saying that there’s a 1.7x higher purchase rate on tablets than on phones for apps. Also, updated versions of apps that take advantage of recent platform additions like the new capabilities unveiled at I/O this year have a 2.2x advantage at monetization vs. older versions, on average.”

Google released the latest statistics in hopes of showing developers the financial incentives of converting apps to tablet versions, and to leverage the latest Android improvements.

“While both methods of earning money are proving to be profitable, Google reminds developers that in-app purchases are still leading the pack, and suggests that those creating new apps should strongly consider focusing on free apps that allow for in-app purchases,” notes Digital Trends. “The theory behind that being that you must first get a user to love your game, and then you can more easily convince them to spend money on it. It’s a swap from the traditional up-front purchase model that has driven gaming for the last 30 years.”