Apple has backed off some of its original demands for such purchases. Originally, apps that sold anything substantive outside the app, like say a subscription to Hulu Plus, were required to offer the same purchase in-app, with a price less than or equal to the outside price. Since anything purchased via the normal in-app purchasing APIs in iOS meant that Apple would get a 30 percent cut ---- well, you can see the reasoning Apple had behind the move.
However, some apps, like Amazon.com, worked around that by redirecting users to Safari and having them go to a site where they could make purchases. Good idea? It was, but it was banned.
Apple made changes to these policies earlier this month. The modifications said that in-app pricing could be set by the publisher. That means that a publisher could make up for Apple's cut by raising in-app prices by 30 percent, if it wanted to.
However, one important ban still remained: no links to external sites in-app. That means that Amazon.com's main app, and its Kindle app, as well as Barnes and Noble's app, would all be in violation, if unchanged.
Just last week, Hulu Plus became the highest profile app to comply with the changes, removing its link to subscribe to the Hulu Plus service.
For now, the Amazon.com, Kindle, and Barnes and Noble apps are still in the App Store. They haven't been updated for a while, which means they don't conform to Apple's requirements. Tomorrow morning, will they still be there?