Have you ever went to a retail place (paint store, auto parts, flooring, etc.) and wanted a deal. Or, wanted to switch a muffler for a muffler even though they have a no return policy? Have you ever painted you house and tried to get a deal because you were buying a lot of paint? When the normal cashier dude can’t help you or get you a deal, he gets you his general manager, and what’s a good general manager do? He takes 10% off and thanks you for being a wonderful customer and buying his paint. He doesn’t explain to you how much it costs him to switch sausage for peppers, or how it will be added labor to tell the line cook to make a change. He just takes care of you. And when you leave you say, that guy does a great job, what a great store.
When the guy doesn’t take care of you, you walk out and say “what was his problem, didn’t he care that I chose his place over the other paint store”. So what if you give away 25 cents on a pizza and and your food cost went from 25% to 25.5%. Your business needs customers, bottom line, and when you take care of somebody they tell their friends, and you get more customers. Someone’s continued business is much more important than their extra quarter on their visit.