Google has confirmed that it's Android app developers who design and market apps on Android Market can now offer extra content for sale from within apps - both existing and new.

Dirk Dougherty posted on the Android Developers blog saying "In-app Billing gives you more ways to monetize your apps with try-and-buy, virtual goods, upgrades, and other billing models".

The news breaks as some app developers have been quick off the mark with in app payment already introduced for  Tap Tap Revenge by Disney Mobile; Comics by ComiXology; Gun Bros and Deer Hunter Challenge HD by Glu Mobile and others too. This means that you can purchase additional content from within the above apps.

The new service is a winner for both Google and the developers.