A virtual Shelfari bookshelf

Amazon.com has acquired social library network Shelfari for an undisclosed amount.

Shelfari lets users showcase books they've read on virtual bookshelves. Books can be reviewed and discussed among "friends," which occasionally form on-site reading groups. Some months ago, Shelfari also made it possible to embed virtual bookshelves onto other websites.

In addition to all that, Shelfari users now have the option of purchasing books they like via Amazon:

Amazon recently bought a 40 percent stake in Shelfari competitor LibraryThing, and purchased AbeBooks, a site where people buy and sell rare books. The e-tail giant is now a solid contender in the book-oriented social networking niche, observed The New York Times, and its recent acquisitions could be leveraged to promote its Kindle product, and associated e-books, to literary enthusiasts.

Where Shelfari is concerned, some spectators believe it will thrive under its new parent, at the very least against competitors. Noting other bookworm-courting rivals will have their work cut out for them, blogger Stan Schroeder of Mashable said, "It's tough enough to build a niche community as it is; if you have to compete against a giant like Amazon, it's 100 times tougher."

Others scrutinized Shelfari's ability to scale. "Whether Shelfari goes mainstream will depend on how Amazon integrates it with its core business and with products such as the e-Reader Kindle," wrote blogger Richard McManus of Read Write Web.

Early this year, Apple CEO Steve Jobs scoffed at Amazon's Kindle, arguing, "40 percent of the people in the US read one book or less last year. The whole conception is flawed at the top because people don’t read anymore."