What we used to promote our project:
We used some PPC advertising (Google Adwords and Facebook) only for first week - we made them on our own.
Good point is to not start the campaign during friday or saturday evening - people are mostly out of PC.
50% backers are from our refferals, other 50% are from Kickstarter itself!
We are trying to write at least 1 update per week.
We use many social networks, forums: Facebook, Google+, Instagram, Twitter, Reddit, Boardgamegeek, LinkedIn, Tumblr, Pinterest etc,
We also informed many bloggers about our campaign.
We are trying to react as soon as possible to all comments and messages.
I hope this can help someone else too