Seems like it would put you in a position to publish a, say, quarterly collection of the results. Combine that with a Patreon or something similar if other people enjoy the stories that come from the prompts, and you might break even while still getting the stories you like :) Seems like most short story publishers run in a deficit so if you're accepting that from the start you're in a better position than most.
I'm actually contemplating doing this. I am a technical person with no time or energy on my hands to build shit in my personal time. So I'm putting together an RFQ for someone to build the site to automate a weekly writing competition with amazon gift cards for prizes. So I was thinking a semi-monthly issue of 8-10 of the top rated stories with royalties (if any sales) to the writers.
