As to why someone posts on quora: http://www.quora.com/What-s-my-incentive-to-post-answers-on-Quora http://www.quora.com/What-s-my-incentive-to-post-answers-on

As to why someone posts on quora: http://www.quora.com/What-s-my-incentive-to-post-answers-on-Quora http://www.quora.com/What-s-my-incentive-to-post-answers-on-... I'm sure that some of that also applies to HN.