You should be good at using business methods. For example, if you have a supper dish that is particularly delicious, you might as well sell it at a loss or at a low price. Diners will always remember what you ate and what you didn't eat, so that you can let more people experience this delicious food. Naturally, it can drive the demand of other varieties. And sometimes when you see a bottle of beer sent by an old customer, the worse your business is, the less you can be mean to customers.