That is so shitty. I sprung for a paper printer because screen signers tip less than people who sign a receipt.
Isn't it? Another of my favorite coffee shops does iPad signing that simply presents three tip options in boxes: 1$, 2$, 3$, with a small "other amount" button underneath. I bet that setup drives more tips than cash even. When tipping is as easy as touching a button it's effortless. But in the absence of that screen option, screen signing will absolutely result in lower tips. No cash change places back in the hand creates too much friction.
Huh. Interesting. I always tip at least a buck when I have cash and with the button that stays the same but sometimes I hit the 2 or 3 dollar one. But I've worked in the service industry so I'm probably a lousy example of the average person even anecdotally.