When I had a Premier AP I used to get the "Club 33" discount on my receipt all the time, so I finally asked a cast member at the register about it. There are some places where the Premier discount was 20% where as the Premium and other AP discounts were 15% (or maybe it was 15% and 10%). Well, turns out when you presented your Premium AP, the cast member had to manually punch in the whole AP # into the register to get the discount...so she said when they were lazy they would just hit their the "Club 33" discount button which gave the same discount without having to enter the numbers!