I think they’ll find a lot of the same challenges:
1. Finding space to have events
2. Ensuring that people who said “I’m going” actually end up going.
3. Bootstrapping groups such that when I stumble upon The Offline Club, I can signup for something relevant to me, happening a short time from now.
4. Keeping organizers willing to continue hosting events
5. Keeping away organizers who see it as lead gen for their sales job
Basically, good luck!Edit: On second look, this is different than Meetup in that it’s not centered around a specific topic … except for being “offline” together, which obviously could create other opportunities for hobbies, etc.