You want your ebook to be both informative and interesting to your readers. Unlike a traditional book, an ebook is meant to deliver information on the specific topic your market is interested in. It should be well organized, with an introduction, table of contents, and chapters that flow in a logical and sequential manner. You will also want to include links to websites, affiliate programs, and other sites that will help your reader to know as much as possible on your subject.
Keep your sentences short. Ebooks are not the place for long, drawn out prose. Your reader will want to get the information they have paid for in a clear and concise way. Avoid acronyms and language that is confusing; many of your readers will have English as a second language and may become confused. Include your contact information so the reader is able to reach you if they have questions about your content. By doing all of these things, you will reduce your return rate and have clients who will purchase from you again in the future.