Not a book site like booklikes and goodreads, but BookDaily.com offers organized samples of new books to readers (and helps authors promote their books via the samples and other features).
Older Publisher Weekly article http://www.publishersweekly.com/article/CA6665072.html?q=bookdaily.com ; links to more press at http://www.bookdaily.com/reference/press .
I'm not an author so clueless about any fee structures for listing/marketing your books with them. No clue about size of mailing list or number of site members. What looked attractive to me as a reader was the organization, the categories (also what I liked about eReader News Today, Pixel of Ink, etc.).