A mailing list in full use with decent auto-responders is a joy to see and literally poetry in motion. If your not sure what an auto-responder is, be sure to check out the link at the bottom of this article. How would you like to sell a product to a customer and then market more of your products to that same customer in the future automatically without having to do anything (apart from setting up a process one time only? Interested? Mailing lists are big business, and lots of businesses fail to see just how important capturing a customers email address can be.