From my knowledge, Quora is not a real social-network, but rather, a world site of questions and answers. (Obviously the language changes according to the country of each user).
However, it doesn't seem so easy to work on Quora!
In fact, the questions are unique (of a single user), but the answers are varied, because provided by many users and them must be correct and relevant.
Quora does not pay directly, but the money it gives to users, they come through its advertising revenue (with a criterion that I don't know yet).
Ok, it pays but, we must remember that such site also requires a certain skill.