BuddyPress.org

I personally always take a group of beta testers, let them test it, if it’s all okay, then I let the crowd in.

At the moment I’m working on a community and the advertisement has been done almost 2 months ago, with a dissapointing outcome that people visited but no one was able to use the website. Probably has the same effect if you make a website and there’s still a lot of bugs, people will leave.

At the beginning of a community make some interesting topics, talk with people yourself and if your community is interesting enough, people will stay.