There's a phrase that gets tossed around a lot, especially in online sales forums: the money is in the list. What that means is you want to cultivate a group of perfect customers for your business and you want to keep them happy. You want to keep them happy with their purchases and you want to keep them informed of new products and new services that are coming out in your industry. Perhaps you want to keep them apprised of what other places are doing. If they are happy, then they will continue to buy and you can go back to this group, this pool of people almost like a well and continue to service them over and over. If you contact them with new offers as time goes on. Not everyone on this list of yours will purchase. But keeping them happy will induce enough of them, if they have an interest in whatever your new product or service is, to make a purchase. This is what they mean by the money is in the list. It's not that you are running door to door constantly trying to find new customers. Although new customer acquisition is something that you should continue to do, going back to this pool of people allows you to draw water from (sales) whenever your thirsty.