Do rude people get some kind of advantage for being rude?

I deal with the public – I’ll grant you that I often see them at their worst (asking for payment after an emergency medical situation with their pets) – but some people seem to make a career of being rude and obnoxious. Do they get their way more often if they’re rude? Do they cause people to relent or just give up? Surely there must be some learning curve that rewards the behavior. Does it affect their health to be so unhappy so often? Surely no one is taught to aspire to being a jerk! How do some people go through life being so unpleasant?