[Aeolun]

Make it useable by asking people to answer questions in exchange for getting to ask their own question?

Reaching critical mass may be harder, but I think it would be more random than mechanical turk.

[hanniabu]

Agreed, answering in return for ask credits is a good idea. Maybe 10 answers = 1 question or something like that. If you make the ratio too large then people will just select anything to get their credits. Another option is to only award a credit if their answer was in the majority.

You can also charge people for the ability to ask a follow up question like why they made the decision they did.