Ihave no idea where you are as you read this. You might be sitting in front of your computer, lounging on a beach in Martinique, or curled up under the covers with a flashlight. But there’s a chance you’re standing in a bookstore with a clerk behind you asking if you need any help. If so, you’re at what we in the book biz like to call the “point of purchase” (POP). From my perspective, the POP is a dangerous place, fraught with ambiguities and temptations. There’s a chance—however infinitesimal— that you might put this book back where you found it and buy a competing title