"Tipped workers" are paid under different rules, and it varies state by state. They typically have a minimum cash wage ($2.13 federally and in NY for example) and an hourly "tip credit" ($5.12 fed/in NY) to bring them up to standard "minimum wage" ($7.25). They only get paid $2.13 an hour by their employer.

More here: http://www.paywizard.org/main/Minimumwageandovertime/Minimum...