Today at the iPhone OS 3.0 preview event, Apple announced a new “In-App Purchase” platform for iPhone app and game developers to sell digital goods and subscriptions inside their apps.

As expected, Apple will control the experience and users will be billed through the iTunes store. Apple said the new APIs from the updated SDK will go live sometime this “summer.”

“Some developers have come to us and talked about other models they’d like to use. Like subscriptions. A place where you could renew that sub in the app. Some game devs have wanted to be able to sell new levels from within an app. There are many examples of that, like e-books. Like a bookstore built into an app. We supporting these new models in what we call In-App Purchase,” Scott Forstall, SVP of iPhone Software, said today at the preview event.

Here’s how it looks:

Forstall said, like with the regular app store, developers can select the price of digital goods in their games and will keep 70% of the revenues, which will be paid monthly.

Photos courtesy Engadget

Now, iPhone app developers have not had any simple way to sell digital goods or subscriptions inside their apps. Those that wanted to sell virtual currency had to refer users to purchase “premium versions” of their apps, that came with virtual currency.

Will Apple open up the payments market on the iPhone for other providers to participate? Many top iPhone app developers that we’ve spoken with don’t expect them to any time soon. For now, however, developers will be very happy to be able to start selling digital goods easily inside their iPhone games.