Came across an interesting story (or I found it so): the proprietress of a bakery in Washington, D. C., got a very good write-up by the Post's restaurant/food critic. The problem is, the write-up included a picture of her doughnuts, which became what all the new customers wanted...and the only item they wanted. Making matters worse, they would only want to buy one or two doughnuts, and nothing else...and would be paying with nothing but twenty dollar bills!
Since the local bank itself had trouble keeping up with the demand for one dollar bills, particularly on weekends, the baker was hard put to constantly make change. She finally had to make a policy change, not to break twenties for just one or two doughnuts. If people wanted that few doughnuts, they could pay in smaller bills.
Typically, some of the people coming in for just one or two of the doughnuts were outraged at being treated this way. One woman waved her money in the helpstaff's face, saying "This is American money!" (The helpstaff was Latino.) Would the woman buy anything else? No, flat refusal there. Even some of the cookies the bakery makes were rejected. The doughnuts were all she had heard about, and those were all she wanted. Next thing, the "customer" was threatening to go on the Internet with her story and make the baker and her bakery look like...well, we don't use language like that here.
Just goes to prove, the customer is not always right. Whoever started that notion had no idea how sadistic some customers can be.