My friend Bando Masako, the Japanese horror writer of Inugami and Shikoku fame, once told me that the best way to secure a sector of the market and have commercial success, would be to create your own niche, your own genre.
“Something like Post-Calvino Italian Literary Fantasy,” she said. “In this way, if someone wants to know what Post-Calvino Italian Literary Fantasy is, they’ll have to buy your books. And anyone doing something vaguely similar, will be someone you ‘influenced’.”

It’s sound advice, and I’ve seen it happen, in both the large international market and the smaller, oxygen-starved Italian market.
Things like Grimdark, of course, or New Pulp, have become wildly successful, and EcoPunk sound promising, while New Italian Epic… ehm, we don’t talk about that.
It’s marketing. Noting wrong with that. The oldest profession.
As Gene Wolfe said “I write the genre that the drugstore guy decides when he puts my books in the wireframe holder – sometimes they place me by Asimov, sometimes they place me elsewhere.”

It was of course a time when drugstores still carried paperbacks.