What's a good tip? 15 percent? 20 percent? Or maybe even nothing? Whatever the amount, tipping has catapulted into controversy for the restaurant business, and a key CEO recently defended the practice.

"We like it from the standpoint of it allows servers to really understand the importance of great service and what's in it for them when they provide great service," said Wyman Roberts, the CEO of Brinker International, the parent company of Chili's Bar & Grill and Maggiano's, in an interview Tuesday at the ICR Conference.