Sell your e-book on Facebook.

if you were wise and wrote a book that caters to the audience you've been building up with your primary account, you've got a receptive, ready-made audience for your sales pitch.
Advertise it several times a day, both blatantly and at the end of other posts. Be creative and try to engage your readers. Get them excited about reading your book.
If you have other accounts (such as affiliate accounts), advertise your book there, too.
Always provide a link for reader to click to visit the page where they can purchase your book.