Say you self publish a book, and then you want to have a launch, with lots and lots of physical books. So, you have a few options for taking payment. An obvious choice is cash. Cash is king, you don’t need to mess around with anything, and you can go to the bar and buy a drink if you make enough to cover one… but nobody carries cash anymore.
You can invest in setting up merchant accounts, getting expensive equipment (usually rented).
Then there’s square. You get approved in a couple of minutes, and you can process credit cards on the spot. No debit, but these days the banks are moving towards visa debit, which processes just like a visa. The fees are not non-existent, but they aren’t all that high either. More to the point, you can swipe a card and charge it, so long as you have an internet connection at the venue.
They also have an online store option. I plan to take a great deal of advantage of that fact – merch is going to be coming out. I spend a great deal of time and energy on the images that go with my stories…