So the Indie Gala guys are trying something new:
http://www.galagiveaways.comLog in through Stream, it calculates (probably badly) the amount of dollars spent on games in your Steam profile and then converts those into points to spend on raffle tickets for free game draws.
You can also sell game keys and such through their system. You get the amount of point you ask for when the raffle is over, plus 5% of the total amount of points spent on raffle entries.
Quite interesting.