This is from a reader’s email. I know if you’re a bookstore you can pretty much order as many Harry Potters as you can, because you know they will sell, but how does a library decide how many Harry Potter books to buy? I do a lot of work in libraries, but I have never been on the book ordering ends of things. I know how librarians choose which books to buy, but not how many. If anyone would like to help out with some simple explanation for my library patron reader, I’d appreciate it. update: Glenn asks a good question in the comments: do libraries want our “old” copies when we’re done with them? I know there are a lot of HPs that are already gathering dust in homes across the US.