The book INCLUDES the short story N
"Book Description
In Just After Sunset Stephen King delivers an astonishing collection of short stories, his first since Everything's Eventual six years ago. One of the longer stories in this book, "N." recently broke ground when it was adapted as a graphic digital entertainment and brought to vibrant life through a series of 25 video episodes"
So it's not an exclusive in that only Amazon buyers get the story N... everyone gets it eventually when the book is released. A bit different than this thread makes it sound