Customers only

Martha and i went over to the local Mexican fast food restaurant for lunch. I wandered over to the bathroom to wash my hands and was greeted by this sign:

This is the first time I've seen the notice up on these doors. I couldn't help but think, gee, you know, if I really, really needed to go to the bathroom, and saw this sign, I'm 100% sure I wouldn't be deterred by a sign telling me that I need to pay before I use the toilet.

How useful are these signs? I mean, I consider myself fairly considerate when it comes to businesses: I try not to waste sales clerks' time if I'm just looking; I use restrooms when I am a customer; I'll buy something, even if it's just a pack of gum, if I have the time and the money.

Yet, in an emergency, those signs mean nothing. In a non-emergency, the sign makes me wonder what motivated the management to post the sign. Was it another few bad apples ruining the management's trust with its customers?

In the end, why bother?