No, this isn't another entry about the Rapture. It's about endings. To books and television shows.
As a writer, the trickiest thing to pull off is the ending. Setting the stage is easy, and it's not that difficult to ratchet up the tension and build expectations for a fantastic climax and resolution. But eventually, you have to deliver, and that's when it gets tricky. You've made a deal with the audience: keep paying attention and I'll return the favor with a killer ending. It's the same kind of deal a joke-teller makes with an audience: stick with me during the joke, and I'll give you a laugh.
It's easy to stick with a joke. You've only lost a few seconds if the joke falls flat. There are cases where you have a Shaggy Dog joke, or any kind of joke in which the object is to waste the listener's time with a drawn out joke that's really a practical joke. Even then, you're not out that many moments in your life.
With books, it's different. There's more time, and often money, invested. Sometimes it's a single book, and the time investment is relatively short. Either the book pays off or it doesn't, and you can move on to the next. Then you get into the book series, and this is where a reader must invest carefully. While each book has an ending, the overall series is building somewhere and you have to choose whether to keep reading and continue to invest your time, money, and energy.