In-app billing is coming to the Android Market. The new service gives developers more ways to monetize their applications through new billing models including try-and-buy, virtual goods, upgrades, and more.
The In-app billing service manages billing transactions between apps and users, providing a consistent purchasing experience with familiar forms of payment across all apps. At the same time, it gives you full control over how your digital goods are purchased and tracked. You can let Android Market manage and track the purchases for you or you can integrate with your own back-end service to verify and track purchases in the way that's best for your app.
In-app billing will be available in stages. Google is now providing detailed documentation and a sample application to help developers get familiar with the service. Over the next few weeks Google will be rolling out updates to the Android Market client that will enable developers to test the apps using the service. Before the end of this quarter, the service will be live for users.