Book-Oriented Social Networks - FiledBy.com

In a 2008 BK Author Tip Sheet we provided links to a couple book-oriented social networks: Goodreads and Red Room, both of which allow authors and readers to interact.  Recently we were introduced to FiledBy,
started by an Ingram Book veterans.  I think they have done a fantastic
job in creating a user-friendly design for both authors and readers. 
What's cool is they have BK books and authors already on their system;
they must just be claimed by the authors in order to provide more
content.  The basic book and author pages are free with upgrade
versions if you want to use FiledBy as your primary website.  So far I
see BK authors Debbe Kennedy and John Perkins have signed up. 

All theses sites claim that authors and their publishers can sell more
books by being active on their sites, both because their own members
find new authors and because the search engines pick them up the book
pages and direct traffic to them.  Do you have direct experiences with
FiledBy, Red Room, Goodreads?  What do you recommend?