“If we don’t have Spotify working properly across Play services and core services, people will not buy Android phones.”
Spotify pays Google 0 percent when it bills users itself and 4 percent when Google does. Everyone else pays 15 percent, or about 11 under User Choice Billing, plus their own processing costs. Google fought to keep those numbers secret during the Epic trial. The fee is not the price of running a store. It is whatever Google thinks you are too small to refuse.