Remember the days of Harry Potter mania? Practically every chain and indie bookstore in several countries had a release party for the latest J.K Rowling tome. Children, teenagers, and even parents clad in cloaks, crooked plastic glasses, and eyeliner lightning bolts waited for hours to get their hands on a copy of the latest book. I was a fixture in these lines, complete in my Hermione costume. We look back at these midnight literary festivities ten years later as a pop-culture touchstone. However, to people in the publishing industry, this is the perfect example of how pre-orders can make your book a success.