As you may already know, Spotify started sending out emails to its customers to stop subscribing to the Premium account through iOS App Store's In-app Purchase mechanism (which costs $12.99) and subscribe using Spotify website (which costs $9.99).
The reason behind this difference is that Apple charges 30% of the
purchase price as its noted here. The purchase price of Spotify Premium through App Store is $12.99. But this doesn't make sense to me. 30% of $12.99 is approximately $3.9 so Spotify will be making $9.1 instead of $9.9.
Is the 30% calculated after the developer states its intended price? i.e. Spotify says that it wants to earn $9.99 with each purchase. Apple says fine, I'll charge $12.99, have $3 (which is 30% of $9.99) for myself and you can have the remaining $9.9. (I don't believe this is the case.)
Or Spotify is actually selling its Premium account cheaper through App Store? What I mean is that in order to earn $9.99 per purchase, one should charge approximately $14.28.
Can someone please clarify the situation? Thanks.