Does Social Media Really Sell Novels?

That's the question I explore today at We're all living in a brave new world where cultural conversation is increasingly shifting to online venues like Twitter and Facebook. But writers are under additional pressure from publishers to use these social media platforms as marketing tools, and many of the novelists I know are secretly wondering whether the time spent tweeting is a misplacement of priorities. As I write in my post, "If an author tweets in cyberspace and no one is around to read it, does it actually sell a book?"