[Dylanlacey]

It's more like you bought a ticket to an event hosted by Apple and while there, Amazon set up a free booth giving away carry bags.

Every time you buy something from Amazon (at the event) to put in the carry bag, Apple takes 30% of the purchase price whilst screeching "WE ALLOWED YOU TO GIVE AWAY THOSE BAGS!"

So, you've paid money for a platform. Amazon showed up on that platform and gave away something for free, taking a freely available booth to do so. THEN they used that to encourage you to buy things from them. And Apple went nuts and demanded they get 30%, even though you paid for entry and they were giving booths away for free.