I remembered some dialogue from the movie French Kiss. Meg Ryan and the cast in the movie said, more or less, “If you treat the French waiter nicely, they will treat you like shit. But if you treat them like shit, they will treat you nicely.”

I used to think that this is some kind of tip on how to deal with the French waiter only. Wrong. You can use the above tip conditionally.  

The meaning of the above dialogue is if you treat the waitress nicely they will assume that you are not a rich person, and you being nice is only a lame tactic to get cheaper prize. This will also mean that you cannot afford to give them a big tip. So, screw this nice person. That is why they treat you like shit.

However, if you treat them like shit, they will assume that you are either just being stuck up or have tons of fortunes in your bank to allow your rude behavior. This means, if they are capable to please you, you will award them with big tips. And if not, you are still holding something for their life. You can either ask the manager to fire them if they are not pleased with you or you can make sure they will not get a decent work anywhere in the world. This is why they treat you nicely. 

My opinion is that it depends on the place. Sometimes, when we treat the waiter nicely, they will response by giving you all the help that you need. Sometimes, they are just simply rude and ignore you completely. It all depends on you as well. Do you wish to be nice only to the right people? Or, do you keep being nice, knowing that they are in the lower standard below you for unable to act decent towards other human beings.