attention industry: Yes, Apple takes 30%
Great exposition on the subject. I decided a while ago that: 1) I was going legit with my purchases and 2) I hated optical media, which has led me to the point of purchasing all audio and video media I consume through outlets created by Apple. I am on the same page as most of the general consumer population, I think.
So yes, Apple is charging 30% of subscriptions within their applications, same as sales happening through the iTunes system. Because, frankly, they are growing your potential market, as a music publisher, a magazine publisher, or a book seller. They are doing what you could not - fixing the barriers to consumption, and barriers to purchase, for your product.
Frankly, you could not have done this yourselves. And if you’d managed to hire the designers, developers, managers and consultants to create this model for you, it would have cost more than the gross amount of the 30% per sale that Apple is going to charge you.