Yes, donation is a much better word for it actually.
Originally Posted by GhanBuriGhan 
I think most people understand rather well what it is supposed to be. Saying it is investing is also wrong, imho - in an investment you have some kind of binding contract what the return of investiment is, given certain conditions. That's not the case with Kickstarter. It's basically a donation, with a promise of certain benefits in return.