Getting paid isn't milking your fan base. This is the same price, near enough, as a new movie on iTunes, or a new album. Users will get subsequent updates to th

Getting paid isn't milking your fan base. This is the same price, near enough, as a new movie on iTunes, or a new album. Users will get subsequent updates to the app until Tweetbot 2 comes out (or Twitter finally do what they clearly want to and round up all of the 3rd party twitter software engineers and put them into a big rocket destined to be fired into the heart of the sun). Apple can rely on the fact that Mountain Lion is a yearly update, they can afford to market and promote the product, and it doubtless has a lead-in for hardware sales too. Tweetbot on iOS is, when you consider the relative size of installation bases for iOS devices and Macs, comparably priced. You can sell an iOS Twitter client at a reduced cost because there are just so many more iOS devices out there. To justify maintaining a Mac codebase you need to charge more.