If you create a community, please try and populate it with content. I see a lot of new communities with 0-1 posts from the mod. That's not nearly enough to get people engaged - users are going to see that it's a ghost town and leave.
If you have enough interest to create a community, you probably know something about the subject matter, so PLEASE add some posts (5-10 would be a good start). Maybe some questions to get people talking, even popular reposts from other sites. It sucks shouting into a void, but if you don't do it, everyone else will also be shouting into a void.
Thanks for coming to my TED talk.