Just to add my two carrots...
When I ran AYAW? at Ubercon VI last year, I had people ask me why I didn't
run larger villages. I calmly explained that I was running it the way LL was
marketing it, as I was representing them (being in my coat and hat/ears). As
such, I only had a certain number of cards, allowing for a certain number of
players.
And that's the point. I was representing Looney Labs. Were I to change the
game to add more players, or more roles, then it wouldn't be the LL version
of the game. The dealers had both the LL version, and another company's
version (with more roles/players). Though people can buy the other company's
game, I'd rather they bought LL's version. So I show them LL's version.
Just like I wouldn't run a GURPS variant of an RPG when demoing for the
original RPG's publisher. Both are good games, but when demoing for a
company, you use that company's products.
Seth
aka GnTar, the evil teddy bear Rabbit