If literature was food then this would be the starving persons feast, well for me it would be anyway because I devoured this and like all great books you enjoy it was over far too quickly (understandably, seeing as it's a novella) and yet if it went on any longer I don't think it would have been anywhere near the same.
There's an introduction by Stephen King (at least in my copy) with a line that I found to be very true "he will leave you wanting more" and if you watch the movie, do yourself a favour and read the book because in my opinion a movie could not do justice to this book especially with that ending.