There were 10 books all coming out on the same day so I think walmart said ok were doing $10 for all of them then by the next day amazon had lowered there prices. Oh and I believe that some were preorder as well. I remember I got the new John Grisham on preorder at like 9 or 9.99. It was a good deal. Here's an article about it. http://online.wsj.com/article/SB10001424052748704322004574477050954174722.html Dana