I've never understoond the change cups at Dunkin Donuts. They always seem to make me feel guilty about using my card, but why should we have to tip a FAST FOOD store? They aren't providing any more of a service than McDonalds or Burger King. I understand tipping someone that WAITS on you, or a Valet/Doorman/Taxi driver who is should be paid accordingly on service. But why should we tip people that hand a product over a counter like so many other industries?