In order to RSVP, you must zap?
Discussion
Mmm maybe not necessary to RSVP, because we have a huge range of skills and knowledge. It'd definitely turn away any newcomers.
Maybe there isn't something more than social signals. Like, "Joe zapped sats to cover the first round."
Have you tried this out yet on nostrcal.com? It will let you set a zap amount before users requests show in your booking page.