Bob Notes is a tumblelog.

If your users, with their shiny MyWebBookSauceHubsterVille account, come to your app from MyWebBookSauceHubsterVille.com, they’re your customers: your marketing got them, you own them, Apple respects that.

If, however, users come to the app from the App Store, they’ve never heard of MyWebBookSauceHubsterVille before: all they’re interested in doing is making their iPad a little more useful. Then, Apple sees them as Apple customers, first and foremost, and Apple wants its cut of the action. You’re standing on top of their stack, and that costs 30%.