Meetup had a way to do this: make it opt-in by organizers, then increasing organizer price later on, perhaps even drastically, to incentivize the new structure. Over a year, say, even on organizers who didn't opt in, they could likely double their revenue per subscription with minimal churn.

Instead, their messaging strongly implied that, while it was still being tested, this would be mandatory, destroying community trust. An absolutely flubbed rollout.

https://www.theverge.com/2019/10/15/20893343/meetup-users-fu...

https://wptavern.com/meetup-com-introduces-rsvp-fees-for-mem...