Does your group description clearly reflect the purpose and potential of this space to your group members?
Have you supported others to register and join your group?
Have you made people feel welcome?
Have you started a thread, added a blog post, news item or event for them to arrive at and engage with?
Have you invited others to be proactive in your group as well?
Have you commented on a post and made others feel their contributions are valued?
Have you helped to share ideas, create resources, unpack research/theories, nurture opinions, views, concerns and wonderings?