Aardvark: Answering the Tough Questions

I have asked a couple of questions thus far and received fruitful and quick replies. The IM/email interface works for me and "subjective search" will be big (if done right).

The only issue: since subjective search is very much a 2-way (person2person) transaction, medium/long term, what is my incentive to keep answering questions with no economic gain?