Stephen King wrote a story called UR that is available only on the Kindle. King said that he was initially said no to writing a story but then he thought it was a way he could write a specific scene.
Paraphrase of what King said about story:
My wife likes to say that lobster is an excuse to eat butter. For me, sometimes, writing a story is an excuse to write a certain scene. Wanted to write a scene about the phenomenon of reading off a computer and the crisis point that at least the press has made between print media...and the evil Kindle.
UR by Stephen King