For an interesting take on how two massively successful corporations operate, just take a look at Microsoft and Amazon. Both companies offer apps that rely upon users buying a subscription. When Microsoft released their Office suite for the iPad, they made it free, but users needed to buy an Office 365 subscription to access premium features. Amazon just bought the comic book reading app Comixology which also lets users buy and subscribe to new comic releases using the app. This is where the similarities end.
Microsoft leverages Apple's in-app purchase infrastructure, as Comixology did originally. Now that Amazon has purchased Comixology, this has changed. Users need to purchase comics using the web site, as Amazon has done for Kindle books. It's interesting that Microsoft seems to have no problem letting Apple take 30 percent of purchase revenue, but Amazon won't stand for it.
As a developer I can relate, because besides losing the extra revenue, we don't get to know our customers. Apple knows who buys what and it's hard to cross-sell. But Apple makes it easy (maybe too easy) to make in-app purchases, so I accept the 30 percent as the cost of doing business. Amazon has a sophisticated shopping system, unlike most app developers, but still they could offer two ways to purchase and let the customer decide what is preferred.
Kudos to Microsoft for making the customer experience come first, even on a competitor's platform, and shame on Amazon, which prides itself on offering a great customer experience, but is making customers jump through an extra hurdle.