I just managed to get a book giveaway to go viral on Amazon. I've been blogging about this to help other publishers and authors as it's hard to get this kind of information online. I've done a few blog posts with exact statistics and the latest has more help as we've learnt from experience and managed it. Hope it helps you http://adeleward.blogspot.co.uk/ The book is Joe Stein's Another Man's World and there are now downloads every second on Amazon UK, so I count it as going viral now the downloads happen even if I do nothing. To get to this point it had to get high in the rankings, and the secret to that is working your way up in the categories. Hope the blog helps.