In-App Purchase offers a great way for your users to enhance your application after the sale by purchasing additional material: new game levels, in-game goods, and subscriptions to new content. For the user, it's just a few taps, and an easy payment from their iTunes account. For the developer, however, In-App Purchase requires a major effort: creating and hosting digital products, developing and hosting authentication servers, managing products in iTunes Connect, and more. Don't let the small size of the Store Kit framework fool you: offering in-app purchases goes far beyond that. In this talk, we'll go through all the steps of selling products through I-AP, pointing out the unexpected benefits and problems that come with it. We'll also reveal iPhone frameworks that, while not technically part of I-AP, are vital for successful and secure purchase-based applications. Finally, we'll look at cases where you might want to use I-AP, and others where it makes better business sense not to.