I did some time waitressing last year and I've had friends and family doing it my whole life. Prof is close, but missing just a couple small details.
At 2.13 an hour it is less than 1/3 of Minimum Wage. Most wait staff don't get more than about $20 to $50 on a paycheck since they take all the taxes out. Some even have to contribute from their tips towards taxes.
DO NOT PUT THE TIP ON YOUR CREDIT CARD!!! The CC company takes out a 3% processing fee. Most customers with a bill higher than about $50 will put the meal on their cards, so in the high end places, most of the tips are CC tips. Most places pay them out at the end of every shift. The one I worked at paid them out twice a month with the pay checks.
If there is an audit the IRS "assumes" a minimum of 8% in tips against your total sales. The place I worked for required everyone to report enough to cover Minimum Wage whether you actually made that much or not(so much for the "employers have to cover Min. Wage" BS). They got pissed at me because I actually reported what I got and it pretty much skewed everyone else's reporting.
Also, very, very few places have full and immediate turnover for 4 hours. Plus, the staff usually is scheduled for an hour or two before and after the rushes for sidework. Also, most waiters aren't getting 40 hrs. In fact, they usually kept at below the hour requirement for providing insurance. Plus, you aren't even getting close to full or immediate turnover except Friday and Saturday nights and the weekday lunch hour at those kind of restaurants.
Honestly, most "Restauranteurs" are not really business people. They are very often people who think because they are good cooks or have great taste or whatever that they would be a great restaurant owner. But, since they aren't good businesspeople, there is a bigger failure rate amongst restaurants than other businesses. A big part of the reason wait staffs get screwed the way the do is because they working for some schmuck who thinks he's gonna be the next Wolfgang Puck without the training, business skills and preparation when he's really just Joe Schmoe "King of the Neighborhood BBQ".