The ONLY time that I tip is if one of the pizza places delivers to me. Other than that, too bad. I remember seeing a video where a restaurant owner chased down a customer because the guy didn't leave a tip. The owner screamed at him, "How the *bleep* am I supposed to make any *bleep* money?!!!!" The guy responded calmly, with "raise your prices," and he's right. Pay people a living wage, dude.
The economy in the U.S. is in shambles. I don't even order in anymore. It's not worth the money at all. I remember when 20 bucks got you two large pizzas, and I would always tip a fiver. Now? No way. Not unless I need food and I can't get to a proper grocery store, and that has only happened once in the last six months.