I absolutly know what you mean.
Being an ambassador (from my point of view) doesnt mean to quit a job and get divorced just to get free time, but to "be there". If it is a tournament once a month or "Mage Wars day" once in two weeks in your local store, consistency or rather Regurality is a key here. Moment ppl get used to the fact, that there is someone out there and that if they buy a game, they will find an opponent/buddy for a game is a moment when you create community. Two is a crowd
I am a Prague ambassador, so if you ever had a travel in my direction, give me a notice