Thanks for the explanation,@fit.zone. We are in full agreement with your view.

Besides, attracting participants based on high rewards would only attract those who would be ever ready to leave in the future to another platform which offers even better reward. It is not a sustainable model.

It is better to attract participants who really enjoy asking open-ended questions and/or answer them. That is the way AskReddit got to where to they are, with absolutely no rewards in the beginning. It takes time, but it's worth it.