I think the past purchase receipt check isn't about the shopper, it's about the person at the register. It is a check to be sure that, at a cursory level, every

I think the past purchase receipt check isn't about the shopper, it's about the person at the register. It is a check to be sure that, at a cursory level, everything was charged, and also to ensure that you have goods you paid for. In electronics stores this was one method of handling inventory shrinkage on expensive components. Costco has never made me feel as if I did something wrong, and they found that I'd forgotten to pick up something from the cage at the service desk.