Communications (Internal) obviously it will take a while to grow. It would be interesting to see the growth curve. One would hope that as more people join the rate would increase since more people know about it and can recommend others to join.
At some point the growth rate will reduce as it reaches saturation, following the logistic curve. I wonder what the saturation rate for a forum like this is, I've the number of ringers interested in knowing about and possibly contributing to serious discussion. It won't be all of the 30k or 35k or whatever ringers but it ought to be a significant minority, at least thousands.
The two Facebook groups have ~3k and ~5.5k members. That's not directly comparable since many probably use FB for other reasons and just added a ringing group as an extra. They host quite a bit of discussion, but I suspect that's 'because people are there already' rather than because it's a good discussion platform.
ChangeRingers doesn't afia publish membership numbers but istr it was over 400 around 20 years ago, when there was far less e-communication generally. It's use has reduced in recent years as some discussion has been diverted to other platforms but I don't know whether it's membership has also shrunk. The email lists are a better comparator for the forums because the motive for joining are similar - at a least it is for the serious ones (change ringers, ringing theory, bell historians). I would exclude ringing chat which is probably more askin to FB than the Forums.
ChangeRingers grew naturally as people found out about it because there was nothing else, but to the Forums has to compete on its merits against other platforms. Convincing people it's better shouldn't be too hard but the problem is changing people's habits. It's easier to stay where you are.
229 Forum users must know a lot of non-users, so can they be mobilised to promote them?