Novel

Interestingly, William Gibson's famous SciFi story Neuromancer was commissioned, and destined to be straight-to-paperback.  It was his first novel and he says he was terrified while writing it, to the extent that he assumed it would be ignored on release.  This attitude, however, gave him a kind a freedom and he decided to write for imagined readers in the future, which could be the secret to how groundbreaking it would actually be.