Our local pizza place has a girl that takes orders. She can give a $3 discount, if she wants to. If she doesn't, I have coupons I can use that give me $3 off. I'm lazy, and rather not go dig the coupons out of the drawer. If she gives me a discount, she will get $1.50-2.00 in her tip jar (it is right there on the counter). If I use the coupon, then no tip.
If the pizza has a goodly amount of toppings, then I throw a buck or two in the pizza guy's tip jar as well.
For $700 worth of take-out food, I would have tipped the chick $20, maybe 40. What's next, tipping 10% at the window at McDonalds?