I learned that at the local theatre complex you can get a free refill on your popcorn.
Wifey dragged me to a movie today and while I was waiting for her to emerge from the power room after the show, a guy sitting just down front of us was at the counter getting his mega-tubba-corn reloaded and re-buttered. It looked like a quart of butter went on after the fluffy corn goodness when in, and no currency was exchanged, cards swiped, or secret handshakes exchanged. Maybe he had a coupon? It looked like it was a free refill to me, but since we don't use popcorn I'm not versed in the traditions regards refills. Maybe it's just on the tubba-corn and drum-o-coke?