Mhmm, i agree with titan actually, it would be kinda hard, you get the people who help one person once and say "Can you vote for me to be mod?" and because they are new and know no better, they will do!
I think maybe if shadow used a ::hide command, and simple watched people in game @ home, it could prove more useful that a simple poll that people may or may not vote in
The other issue in a vote would be that some may NOT vote, and a person that deserves it may not get it because of the people they helped's laziness.