What Apple actually said (emphasis mine): "We are now requiring that if an app offers customers the ability to purchase books outside of the app, that the same option is also available to customers from within the app with in-app purchase." What ars interprets that to mean (emphasis mine): "If an app lets users access content that they purchased via Amazon's website, for example, then that same app must also let user…
Apple said if the app lets you buy books outside of the app, i.e. you click the buy button inside the app and are then sent to the webpage to purchase the book, then the app must also let you purchase the book without leaving the app by using in-app purchases. Okay. But they also said you cannot buy books inside the app unless Apple gets a cut: http://arstechnica.com/apple/news/2011/02/change-in-apple-po... It appear…
It doesn't at all and I totally agree with you on that. I was just making it clear what Apple actually said because everyone seems to be latched onto the "Apple won't let you access your own content if you didn't buy it from them" fallacy.
Obviously Apple wants in on the purchasing action, and by forcing both actions to be available (staying in-app to purchase or being sent to a web browser) they are hoping at least some people find in-app purchasing easier/smoother and use it instead.