I have a 21 year old son, a hard worker, that is a waiter in a sports bar. It is unbelievable how many times he gets stiffed. Just yesterday he waited on a table of 7, for 4 hours, their tab was $89.46. Guess how much his tip was? Just guess...
I'm a tip-o-holic. I tip everybody all the time, usually quite generously. People who stiff on tips are rodents IMO.
...it is easier to ask forgiveness than it is to get permission...