Note that recognizing and meeting recurring needs of regular customers are a business' bread and butter. Your patron can, most likely, go one block over and get the same product; you remembering that they like lemon rind with their coffee, for instance, and having it for them with a smile, is what keeps them coming back. Also, being prepared to be friendly and take the time to at least ask them how they are makes all the difference between using your business over another one.