my buddy here at work used to be a regoinal manager up north and he was responsible for making several stores at a time increase their gross income by 20% a year or they "failed". adding more than 100k a year. I didnt think they made 100k a year!
I worked in one once... One summer in college... Believe it or not, my store would average about 1200 a day. This was almost 20 years ago. I couldn't begin to tell you how.