I am about to conclude that using Meetup as a method of setting up a local group is a dead end. I think Hiram reported something similar, and I know that my own efforts have yielded nothing. I also gather that Elayne's success has been limited.
Possibly the issue is that the type of person who frequents Meetup is just a casual user looking for something superficial (like Stoicism at the deepest). Even if such people attend an initial meeting or two, they are likely to drop away when they find that Epicurean philosophy challenges them in an uncomfortable way.
In my case I made very clear on my opening Meetup page that the group was not general philosophy, and not Stoicism, and gave details about what it is about. If that scared away people and caused the lack of response, then so be it. Even with that, I got notifications that eight people indicated interest, but I could never get anyone to commit to an organizational first meetup. Probably what's necessary is to go ahead with at least two people (preferably three) at a public restaurant, and then see who is too shy to reply, but actually shows up.
I suppose Meetup can be one arrow in a quiver to use, but relying on it as a primary tool is probably not a good idea.
Which means alternate methods need to be developed.