[RHSeeger]

It's worth noting that servers at restaurants are required by law to make minimum wage. If their actual wages (the minimum the employer can pay them, called the "basic cash wage") plus their tips do not bring them over minimum wage, then their employer is required to make up the difference. So if nobody tips, the business winds up having to pay more.

So you're likely hurting both the worker and employer, and making it more complicated for both of them.

Specifics (basic cash wage value, etc) vary by state.

[Frondo]

Anecdotally, from my friends who work in the service industry, this is also a law that is often simply ignored -- so in lean shifts, workers can go home with less than federal minimum wage. Not a good scene.