To get a community going, you need a base. The base is a core group of regular participants.
This core group doesn't have to be big, perhaps it's 10 participants, perhaps it's 150? Maybe it's 500 (we generally aim for between 50 – 150).
Your sole aim when starting a community is to build that core group.
Nothing else matters; not technology, not content, not big promotional ideas.
Because the base doesn't have to be big, and you only do this once, every new regular participant is a big win.
This means, at this stage, you must spend a lot of time focusing upon one person at a time. If you don't build this base, your community fails. Strip your community management process from all distractions.
It's only once you've built this base and reached critical mass that you shift to macro-level interactions.
The old model of launching a platform and spamming the web to get thousands of visitors is dead. I'm not sure it ever worked in the first place. It doesn't build a base. If you want a high-profile failure, spam the web. If you want a steady success, focus on getting one active member at a time.
It might seem like a slow way to start, but it's better than the alternative.
If you want a free ebook about launching a community, click here.