I own a small Pizzeria and Bar in Chicago near Loyola University.My bartenders and servers are paid $5.00/hour.From credit card purchases I can see that most my staff make an average of 30 % gratuity.Not bad in my eyes,and...they deserve it.Though my place has been around for last 40 years and the local regulars tend to tip better as it is their "watering hole",even the kids from Loyola,be-it on Mom and Dad's dime tip very well.
I have an almost non existant turn over rate with staff as i treat them well and obviously our customers do too.