Tipping is out of control. If someone is charging me for a particular service or good, and the person supplying it to me either is a business selling that service/good, or a person cashing me out for that service/good, then I shouldn't be asked to tip. It's insulting. Tipping is reserved exclusively for those who work for less than minimum wage, under the law, because the law anticipates that they will earn and report tips as their wages.