It's interesting that the tipping customs in North America are so much more than elsewhere in the world. Is it our merticratic pay-for-perfomance culture?
I'm not so sure, since a number of the reasons given for tipping well (servers have to tip out, they don't get paid a normal wage, etc.) have little or nothing to do with the quality of the service received. The language is that of entitlement rather than earning.
You can compare a tip to a performance bonus for white collar jobs, but there's a few key differences.
- While white collar workers might count on the bonus; their base salary is considered sufficient. Not so for service staff.
- A patron having a tough month who leaves no or a poor tip is a jerk. A CEO for a company having a tough year who lowers or eliminates bonuses might not win popularity contests, but will be considered prudent.
I think Keifus touched on the answer below. Since we all consider ourselves above average tippers, we walk away from these situation thinking we have some good. It's not quite a Travis Bickle fantasy, but I do think we think to ourselves, "Other people don't appreciate how hard she's working and how unfair the compensation system is. But I do, and I'll make it up to her."
So everyone leaves happy.