One of the best things about the organizational model being used by Toronto350.org is that once we find energetic and interested volunteers, they usually end up doing a great deal with us: joining the executive, running events, and helping with the many tasks that are necessary to keep the group running. We have had people attend their first planning meeting one week and join the executive the next.
Since every individual interested person who we recruit has such promise, even recruitment drives that yield only a couple of new volunteers can do a lot to maintain and expand our organizational capacity.