Those certain people who deside that they need to go out to a restraurant to eat and rack up a $100 check then also deside not to tip the server.
Bob brings his family out to eat at a restraurant and the bill is $150. He pay with two $100 bills and gets $50 in change. Leaves without leaving so much as a penny of the change his server knows he has. He is therefore a stiffler.