Looks like Quora is a contributor to Forbes[1], but that no one gets paid[2]. At least that's what the answer that I can read without signing up for Quora says...
[1] - http://www.forbes.com/sites/quora/2013/07/08/what-does-it-ta...
[2] - http://www.quora.com/Quora/When-a-Quora-users-content-is-rep...