That's a question that will be tough to answer for some time given that Riffle, a social media tool for book discovery, is still in its invite-only phase. To get an invite and test things out for yourself, visit Riffle's site HERE
What is Riffle?
Riffle is a tool created by New York-based Odyl (who has worked with publishers to create marketing content for Facebook) to help readers with the book discovery process. In the beta phase, Riffle wants to assemble a group of users who are serious, dedicated readers-- and who have a willingness to share their expert opinions. The goal is to create one simple online source that is integrated with Facebook where avid readers can vet content.