That is great insight Baloo - many thanks for sharing your experience. Probably what I hear most of all here is that there is no replacement for patience, persistence and time. It's great to get feedback from a veteran of 8 years of community building.
I see how much time you put into nurturing the forums here on UNA.IO and I don't doubt that you give a lot to your own community as well. I would add to my own experience that there is no single 'one big thing' that is going to make your social community succeed - but 100,000 little things, applied over time, which will help it grown health and tall.