I never unsubbed from CoH, even in the months I wasn't playing, because it was always "my game". I wouldn't even have to think before committing my sub fee to something that could save the game (I speak for my husband too there). We would definitely contribute to a crowd-funding project as much as we could, even we could manage $100 or so - and anything creative we could contribute would be given without a second thought.
BTW, your number one reward for sponsors: Reserve a name pre-launch on a new server. I swear to god, we would buy them for each other as birthday presents.
(Number two would be a sponsor badge. I recommend "Built This City", but I might be biased since my favourite character has a rock theme ;p)