Very nice name for an independent marketplace that may be diminishing a bit, nevertheless book reviews remain an important element in book sales and promotions.
With so many book reviews being published on large bookseller sites an independent " book review " site may have less impact than years prior.
While the extension might likely further limit its' overall appeal - the name and extension look pretty good together - at the least suggestive of a book " US " centered or published IMO.
Value - guesstimate - maybe low - med xxx.