1)  Inadequate incentives – Don’t be cheap.  Think about what it would take for you to change your behavior and invent accordingly.
2)  Inconsistent promotion – Talk about it…all the time.  Most programs run out of gas because people get bored and stop talking about them.  Don’t forget, you may have talked about it a hundred times but it may be the first time someone else is hearing it.
3)  Wrong incentive – Maybe they don’t care.  Maybe they just don’t care about what you think they should.  Ask them.  A quick survey or informal poll.  Find out what has value to them and they’ll care.
4)  High hurdles – It’s human nature to give up when something seems impossible to accomplish.  Make your criteria clear, comics and attainable.
5)  Lack of commitment – Don’t start something you can’t or won’t finish.  The surest way for a program to fail is for people to quit on it.