I think this post is right especially in two regards. First, it gives Amazon information about what people are reading even when they aren’t buying through Amazon. But two, and more importantly, Amazon’s reviews are a mess. No one trusts the Vine people. The people who give one star because there’s not an ebook or because they can’t understand some basic premise of the book are annoying. And Amazon’s recommendation engine works on what I’ve looked at on Amazon and what I’ve previously bought, not what I actually read and liked.
Goodreads solves a lot of these problems for Amazon. I see on Goodreads people whose views I ostensibly trust and maybe agree with because I’ve chosen to follow them. I see their reviews of books first and only occasionally have to stumble across idiots. And Goodreads does a good job of helping me find books I might actually want to read.
That seems like a real win for Amazon.