Apple enables free apps to charge for micro-transactions
Now however its removed this restriction, allowing developers to release free games and make their money using micro-transactions, which is the standard model with massively successful online games such as RuneScape, as well as Facebook and MySpace games like Mobsters and Farmville.
As part of this switch, Apple has also relaxed the limitations for Lite or free versions of paid apps.
Now developers can create one free app in which additional paid functionality is unlocked by micro-transactions, easing the development process, which up to this point has required them to submit separate paid and free apps.
Apple also pointed out in its note to developers that using in-app purchases can help them combat piracy as it forces users to access new content via App Store transactions.