[breischl]

At a different level that's part of the reason receipts exist, and why you occasionally see things like "if we don't give you a receipt your order is free."

In those cases it's typically about preventing the employees from not ringing up the sale and just pocketing the cash. The receipt proves that the order was entered into the system. Same idea, just a difference of who's stealing from whom.

Hm, I suppose that scam is less of a problem in the era of credit cards.