[richardknop]

What about billing support? You need people on the phone to handle complaints and issues from customers, deal with chargebacks, refunds and thousands of various weird requests from people that will keep coming. Also you need a software engineer team to work on the payment processing system / website. It's not "build it once and leave on autopilot". These things need continuous maintenance, bug fixes and improvements. All of that costs a lot of money and you have to have a really large revenue to be able to handle this yourself.