"Chick-fil-A is a contrast to the current QSR strategy that involves broader menus and more complex operations. Chick-fil-A's unit volumes exceed $3 million. That's the highest average of any limited-service chain out there. It's higher than Chipotle, it's higher than Panera Bread and, yes, it's higher than McDonald's. Indeed, Chick-fil-A does those unit volumes with half the menu of your typical Golden Arches and it's not open Sundays or holidays."
Why Chick-fil-A Just Works - Restaurant Industry Insight, News and Analysis