Amazon is not only a place to sell your book. It is a place to post a Blog. Amazon has a new sponsored link called "Filedby" that includes an author biography page where you can post a Blog and relevant articles. Also within Amazon, each content section has forums in which people start topics or respond to the topics of others. You can post messages and responded to messages in Amazon forums as wide ranging as history, fiction, war, romance, art, science, religion, literature, etc. Again, each time you write, sign off with your name and the title of your book. You will instantly reach thousands of potential buyers.