that you flip around and let a customer fill out results in easy money for the restaurant. Either the tip goes to the topline for the restaurant or it goes to the employees (hopefully the latter). If it goes to the employees the owner can get away with paying a lower hourly wage.

I don’t know what the data shows, but I would guess about half of customers cave in to the pressure of leaving at least a small tip. Quite possibly a lot more considering how convenient and less awkward it is to just push one of the tip buttons instead of selecting “more” and then entering zero.