Finix targets customers that process at least $50 million in annual transactions, a point when it might start to make economic sense to move away from Stripe, Square or PayPal. The fintech giants charge merchants from 2.75% to 2.9% of each transaction, plus other fees. Finix makes money through a monthly licensing fee and other surcharges, like an onboarding fee.

https://www.forbes.com/sites/jeffkauflin/2019/07/16/fintech-startup-finix-raises-18-million-aims-to-become-the-twilio-of-payments/#524fbe343e02