When I write fiction, I write at the intersection of flash and novel length stories. My domain is political thrillers and noir cop stories. Back in the 1940s and 50s, these stories were written to fit in the pages of the pulp magazines and later on in the mid 50s within the pages of Playboy. These thrillers and even the early James Bond stories were written in episodic format and published in multiple parts. Now with Kindle and iBooks one can publish these shorter stories directly online for the consumer to buy.
Not sure how this would fit into your domain of erotica but I think there is a medium between flash and super long form. Give it a try.