In order to push adoption it would be ley to get some kind of gamification for different kind of activities
Similar to what is being proposed by badge ville you could give points to people when they fill their profile, comment or create post, ask a question, answer to a question
Point could be different according to the bahviour you want to promote
You could get some badge levels and a leader board that show top influencers
Klout.com is eg looking at your social activity and compute you an influencing score
