How to Stop GrubHub From Stiffing Your Favorite Restaurants
by David Murphy from Lifehacker on (#4MYRH)

Generally speaking, restaurant phone numbers you find on Yelp are the entity's actual, real-world phone number. But there's also a way to dial the wrong number for a restaurant, which connects you through Grubhub and allows the company to claim referral fee for anything you might then order.