Why we need an independent reading and reviewing social network

‘All your books are belong to Amazon’. That’s the problem now that GoodReads has been bought by the biggest online bookseller. As Brian Ford says on ReadWrite:

There aren’t many popular social sites for books that aren’t in some way or to some extent under Amazon’s thumb: Shelfari, Goodreads, AbeBooks, and LibraryThing are all owned or partially owned by Amazon. Amazon’s brilliance is in allowing these purchased sites to run quasi-independently: The illusion of competition is there, but it’s just that and, ultimately, all roads lead back to Amazon.

So can you, dear reader, recommend a site that could fill this gap, or will we need to create it for ourselves?