I wrote this post for AutopilotHQ an email marketing SaaS company. 

Please check it out here: https://www.autopilothq.com/blog/grow-your-online-community/ 

1. Curate Good Content

2. Host Events with Industry Influencers

3. Show Off Your Best Content

4. Mention Influencers 

5. Keep An Ace In The Hole

6. Host Live Events

7. Community Alerts

8. Create Original Content 

9. Optimize Content for Search

10. Experiment with Tweeting Frequency

11. Send Personal & Relevant Emails

12. Boost Facebook Content To Drive Member Signups

13. Show Up Day After Day

14. Get To Know Your People