Sound off if you have your own Web site (or one specifically for your book). Your publisher's site doesn't count. You must be master of this domain. Mine has two URLs: CrimeFictionBook.com
Twitter and Facebook don't count. Blogs, well, OK.
Following up question: How did you build it? Was it free online software? Did you pay someone to build it for you? I made mine using webs.com.
Let's hear them.