Today is officially a Harry Potter themed day. Deranged parents permit their offspring to don fancy dress and pretend to be some favorite character from the books penned by J.K. Rowling. Long lines snake through book shops, people sit up half the night reading, and some of the more savvy turn to the last chapter and settle things before bed.
Publishers watch the end of the line pick up copies of the seventh in a series and bid the readers a fond farewell. They didn't know this would happen when the first book was laid out on tables and shelves. They don't know why exactly this happened, that there would be such an enormous surge of buying and profits stretching lazily across the bottom line. The big houses wipe away collective tears of sorrow, knowing that because of all they do not know, they cannot easily replicate the success of Harry Potter.
Simple tales of good and evil, mixed in with highly imaginative characters and scenery....that's about all that it is. Well written, but not in some fancy, highly literate "I'm so smart and you're too dense to understand my prose' type of word-play.
Gamblers know the odds and play accordingly. Publishers, on the other hand, can't quite read the hand they've been dealt. As a business model, it's not the sort of thing you'd want to invest your pension in, but what a wretched world it would be if they ceased to exist.