Post fast on good news or bad. Someone say something bad about your product? Link to it - before the second or third site does - and answer its claims as best you can.
Unfriend people who do not post to Facebook or engage with anyone else. You'll find your posts start getting reach they never did before. Why? Facebook only releases your posts to a few people at first and watches what they do with it.
Use photos and videos often. The best startups post lots of imagery and videos. The worst ones? Text only.
And every time I post on it, my new content goes to the top, and the old content moves down the page.