Ask HN: Influence at Scale

Recently I've been thinking about this question: How does influence work at scale?

But perhaps a bit of background first. After participating in (and partly leading) the local chapter of a volunteer organisation for several years, I joined the organisation's national leadership a few months ago. I thoroughly enjoy the work there, but as a team we frequently face questions like: How do we spread the word about this project? How do we get our members to think about this issue? How do we get individuals and chapters to contribute to this plan?

I know how to lead a group. But how do you lead when you cannot talk to (or even know) everybody in person? Every once in a while, I do have opportunities to interact with members and group leaders from other chapters; and obviously we have communication channels to reach all our active members (print, email, etc.). But these options are either impersonal (in writing) or indirect (only reaching individuals, not the whole group).

So under these circumstances, how do you spread your message?

If you have any thoughts on this, or (even better) recommendations for good books, I'd be happy to hear them!