You know your industry. Whether you sell furniture, gifts, plants or even cleaning supplies, there's a market for your knowledge. Publishing E-books allows you to offer this information on your Web site while attracting potential customers. You can use the E-book in your promotional materials and also tie it to your product line. The key to E-book success is to find a hole in the industry and make your E-book's topic cover that area. You're not writing a book on your own products.