When I was a little kid growing up on Lawn Guyland, I'd go shopping with my mom at the A&P.
One of the everlasting memories I have of those trips (other than the intoxicating aroma of freshly ground 8 O'Clock Coffee) is a sign over the manager's office:
Rules of Business
1. The customer is always right.
2. See rule #1.
It's as simple as that.