One big mistake we made at Powerset was to keep everything secret and fuel the hype machine. I think that in the end this was harmful to the company image. It would have been better to get the tool out in front of people, show them what we could do, and let them see the progress. That way you can get people behind you, cheering you on, instead of having them get bored with all the unproven claims you keep making.
Ideas are cheap. Implementations are what make or break a business.