Goodreads immediately became Amazon's social networking crown jewel when the retailer acquired it in March 2013, and in the past 9 months it has continued to grow unabated.
Earlier this week they posted an infographic which touted their success over the past year.
This online community now boasts nearly twice as many members as they had at the end of 2012, and those members were terribly busy. Over 294 million titles were added to member's bookshelves in 2013 and 20 million pages were read in the past calendar year. Book reviews topped 29 million.
Amazon had been investing in book-focused social networks for some years before they bought Goodreads. They had launched their own network at Kindle.Amazon.com, acquired a partial interest in LibraryThing when they bought AbeBooks, and Amazon also bought Shelfari in August 2008.