The deal is good for single-patty cheeseburgers only but there's no limit on how many you can use the discount on.
A Sonic Cheeseburger consists of American cheese, crinkle-cut pickles, chopped onions, shredded lettuce, and sliced tomatoes on a beef patty with your choice of mustard, mayo or ketchup (you can check out my previous review of their cheeseburger here). They normally go for around $3.50 or so (may vary).
Photo via Sonic.
