<a target="_blank" href="http://www.goodreads.com">Goodreads</a>, the social reading service that <a href="https://techcrunch.com/2013/03/28/amazon-acquires-social-reading-site-goodreads/">Amazon acqu
<a target="_blank" href="http://www.flipboard.com">Flipboard</a> has added one more content source to its social reading app, and in the process has opened up another revenue stream for the company a