[throwaway198389]

Your post makes the case for itself, 30% of $13.32 is not $3.33. As Spotify raised their price to counter the apple fee, the also had to give 30% of that raise.

To get $9.99 (for the first year at the 30% rate) it'd be

Spotify fee: $9.99 Apple fee: $4.28 Total: $14.27

When they were charging $12.99 on iOS Spotify was only taking home $9.09 and Apple getting $3.87.

Really goes to show the insanity. Apple probably made more from a Spotify user than an Apple music user. (Of course, they're happy to have an Apple music user for the increased lock in.)

(But as others point out, Spotify showing this almost certainly wouldn't be permitted by Apple).