Typically blue collar and middle class people. They had enough money to tip, weren't saving it to rush out to buy a case of Keystone Light before the liquor stores closed (see drunk frat boy above), and knew they weren't changing my world with a 50 cent tip (see rich people above). Businesses also tended to tip pretty well especially if they were stuck at their workplace for lunch and their choice was an empty vending machine save for an apple and two packets of microwave popcorn or a pie.