She gets 10% if creators choose to use her service as opposed to the dozens of other similar services, some of which charge more and some of which charge less. Hence, there is no antitrust issue.
OTOH, App developers don't get a choice for iOS. They must use Apple's payment system. They don't have a variety of payment processors to choose from. There is no market determining whether 30% is fair, and that is why antitrust regulations may apply.
What if I want to start an app that helps creators manage their Fanhouse content? Should I ask Fanhouse for a cut of their fees so that I can pass on 90% of gross earnings to creator?
That is how many B2B relationships actually work; you've described a referral arrangement in which one company refers a paying customer to another company and in exchange for their referral they get paid a percent of the revenue derived from it.
OTOH, App developers don't get a choice for iOS. They must use Apple's payment system. They don't have a variety of payment processors to choose from. There is no market determining whether 30% is fair, and that is why antitrust regulations may apply.
What if I want to start an app that helps creators manage their Fanhouse content? Should I ask Fanhouse for a cut of their fees so that I can pass on 90% of gross earnings to creator?
That is how many B2B relationships actually work; you've described a referral arrangement in which one company refers a paying customer to another company and in exchange for their referral they get paid a percent of the revenue derived from it.