Maybe have a separate fiction part of Medium? At the moment, most of the stuff on Medium can be considered non-fiction, and I believe most readers come here for that. This part should stay separate from a fiction part. However, if you make a separate fiction part and make it more explicit, it could attract readers (and writers) who want to read/write fiction. So my proposal would be to have two Mediums (but part of the same site), a non-fiction one and a fiction one. This would make it much easier to navigate and help the readers/writers of fiction find and produce what they want.