I worked my way through college serving in a medium chain restaurant (think: better than Chillis, below Mortons).

JayhawkCO is completely truthfull that there are times where you could walk out of the restaurant with negative money. The restaurant only pays you $2.13/hour. The $2.13/hour quickly gets eaten at by tip-share and taxes. When your tip-share is a % of sales (and at our place usually $5-$10 per food runner, regardless of how busy it was) its very easy to get into the negative territory on a bad night. The restaurant in essence doesn't pay you "nothing" but your tips are subsidizing their meager wages to those who don't directly earn tips (bussers, etc.) through tip-shares, which push you into negative earnings.

Someone commented earlier about declaring cash tips for taxes. Many restaurants are now on electronic systems. At our restaurant if you went below a certain threshold of reporting cash tips you'd get written up. The restaurant knew on average you'd make at least 12% after all tip-outs so if you declared less than that you could get in-trouble or fired.

For anyone who thinks a 15% tip before tax is a "good" tip, you're wrong. If I got 15% pre-tax (so lets call it 13% post tax) I probably would not have been too happy. 15-20% after tax was OK and above was very nice.

Servers remember the bad tippers too, so beware. ;-) As I think they said in the movie Waiting "Don't f*** with those who are handling your food!"