Sooo ... for someone who will never use DD (or any delivery again) ... what does it run ya? Say ya order a $20 pizza ... and want the driver to get a $5 tip ... approx.
I remember when Dominos appeared back in college (dorm life) ... a large 1 topping was 6 bucks ... NO tip, and ya hoped it took 30 minutes and 30 seconds .....then it wuz totally FREE
Tipping was unheard of back then (here) ... except 10% at a sit-down, waitress service joint.
I still think Barney should have gone back to the diner and retrieved that extra quarter they left on the table

.
Times change....