And so forth. No longer beginners, with some experience at conference networking, they are ready for the nationals. Developing performers who shell out to travel to a conference and then DON'T PLAY are wasting their time. Stay at home and don't play, it's cheaper. But if they arrived without scheduled appearances every day, they MAKE their opportunities by networking upon arrival.
Showcases often have dropouts and schedule changes that leave room for an extra performer.
Showcases need people to hand out leaflets, do pretzel runs, man little sound boards, etc, and will often barter a playing slot in exchange for the labor. Failing that, jams in every lobby. They carry Vic Heyman's spreadsheet like Scripture, but aren't afraid to go beyond it when someone is wailing an amazing blues number from an unlisted room marked Manchurian Candidates Showcase. HAS FUN and leaves room for some pride and enjoyment of the amazing concentration of folk talent, wisdom and energy brought together into one building for one weekend. I hope this gives you a few things to think about.