And that is relevant exactly how? The app cost has to cover the development and maintenance costs, marketing, any overhead and expenses (like bills, electricit

And that is relevant exactly how? The app cost has to cover the development and maintenance costs, marketing, any overhead and expenses (like bills, electricity, those expensive Apple computers), etc. That's the majority of your costs, not some imaginary distribution costs that you don't have because you aren't shipping a physical box. Oh and taxes too, which come out of the revenue too. And if I remember right, you are taxed on the value of the sold goods, before the 30% Apple cut (so you pay tax from that too, even though you never see the money).