Interesting. Something I've considered doing, though I'd first look at how to avoid the problems with these systems that the sibling post mentioned (how to get the initial investment, how to enable artists without a reputation to earn pledges, how to guarantee output once the threshold is reached, how to pledge in a binding but revokeable way, etc.) How are you working around these issues?
Doing something similar.
Hit me back at the address in my profile, if you would.
It's serendipitous that you bring this up, as I am currently working on a startup that uses this very method!