Last time at Borders

I was at Borders this afternoon, looking for a Cooking Book. Not that I intend to cook, but just thought it might be useful to have one in the the kitchen. As I was watching around me I noticed at least 7 different Best Sellers on the same shelf ans started to wonder whether I had failed to understand the word "Best". Hence the title of my blog: How can so many best sellers stay on the same shelf?