That would subject each service fee component to competitive quality/demand forces within Apple, e.g. app search, trials/CRM workflow, app distribution. Developers and users can both exert choice on the subset of fees applied to a transaction, so they can provide performance-based feedback to Apple.

Even a monopolist can compete with itself, to improve service and product.

Before that carriers had much higher fees when you sold J2ME apps on feature phones through thier store.

I said it was extortionist, not baseless. Of course they deserve a fee. But it's extortionist in the sense that you have no choice, if you want to sell to worldwide mobile users with deep pockets. Apple also forces as many payments as possible to go through their network, and bans apps that try to take payment outside the store if the app does not provide sufficient justification. In fact, they could just probably charge 50% and developers would keep paying them...

> Steam charges 30% to be on its store

Pretty sure Steve Jobs didn't set the 30% price point by looking at the Steam store, lol. More likely it was the other way around and Steam is 30% because the App Store is 30%...