I'm not sure if this is good or bad yet, I've seen several authors posting that its bad for the publishing world, here is the article from New York Times -
Amazon, the dominant online bookseller, said late Thursday that it would buy Goodreads, the most visited social media site built around sharing books. The companies did not disclose a purchase price or other conditions of the sale, which will close in the next quarter.
With bookstores closing, Internet sites have become critical places for telling readers about books they might be interested in. This deal further consolidates Amazon’s power to determine which authors get exposure for their work.
Until the purchase, Goodreads was a rival to Amazon as a place for discovering books. Goodreads, which is based on networks of friends sharing reviews, was building a reputation as a reliably independent source of recommendations. It was also of great interest to publishers because members routinely shared their lists of books to be read.
By contrast, Amazon had several well-publicized cases involving writers buying or manipulating their reviews on its site. As a result, authors said Amazon was deleting reviews from its site at the end of 2012 as a way of cracking down.
The deal is made more significant because Amazon already owned part or all of Goodreads’ competitors, Shelfari and LibraryThing. It bought Shelfari in 2008. It also owns a portion of LibraryThing as a result of buying companies that already owned a stake in the site. Both are much smaller and have grown much more slowly than Goodreads.
Otis Chandler, a founder of Goodreads, said his management team would remain in place to guard the reviewing process that had made the site attractive to its 16 million members. “Amazon has a real history of building independent brands and running them as independent companies,” he said in a phone interview.
Reaction online, however, was swift and laced with skepticism. “Say hello to a world in which Amazon targets you based on your Goodreads reviews,” Edward Champion, a writer and editor, posted on Twitter. “No company should have this power.”
The deal did get some support from Hugh Howey, whose book “Wool” was originally self-published on Amazon and promoted through Goodreads and became a best seller. “The best place to discuss books is joining up with the best place to buy books — to-be-read piles everywhere must be groaning in anticipation,” he said in the companies’ news release.
Russ Grandinetti, Amazon’s vice president for Kindle content, said the integration of the companies was beneficial. For example, it will make it “super easy,” he said, for authors that self-publish through Kindle “to promote their books on Goodreads.”
New York Times