Having a large list of opt-in email subscribers can be one of the best assets in your business. These people are genuinely interested in your website and/or newsletter, and that means that they are all potential customers. However, some people do not utilize their lists the best that they can simply because they do not know what to do. There are things that you can do and maintain that will keep your list interested and growing, and there are also things that you can or do not do that will make your list dwindle.