In order to build a sustainable community, you must get to a place where your members feel comfortable and think of your place built for them when sharing that photo or tip or guide on the community you built for them. Progressive enhancement is the human way to increase relevance of your community for search engines, social graphs, bots, algorithms and yes, humans. You can do this for your community by channeling the traffic back into the network and reintroducing relevant content to those new members and visitors which might find it and the dialogue which occurs useful even, five years in the future..
Tom Humbarger has written a fascinating read on the importance of active management to the success of an online community.One of the most interesting sections to me is the Google Analytics snippet. We don't often get to compare our network metrics to others. In a year and a half, the group grew from 0 to 4,000 members, and in the final full year saw just under 200,000 pageviews.