StingingVelvet: You know, the point of them giving you keys for Steam is not for you to hand them out to people so they never contribute something to the devs.
I think for some people, they can't afford to give much to the bundle and are too embarrassed to give the little that they can but don't mind accepting gifts and I don't mind helping them out.
For me it's give and take - I wasn't ashamed to only throw one dollar at the last bundle but I had previously purchased Isaac and Blocks at release price.
Of course, if I had more money to play with I would've went back and threw in another five for the sake of Voxatron and that platformer (just as good as Voxatron IMO).
It really depends who you're handing out to - the kid I handed mine off to had all of four Steam games and two of them were the free to play ones.
I've found that you have to be careful how big of a leap of faith you take with an independent game that has no demo - I shop a lot at Indievania where the risk is only $1 to $5 and doesn't hurt too much if the game doesn't work.