My answer to Why should I provide my knowledge to Quora for free?
Answer by Jeannette Marshall:
Mentoring others, whether it be online through a Blog, volunteering for new colleagues or on Quora is a way of reinforcing the skills you have and by sharing, it serves as a reminder to yourself.
The long term benefit is that you develop your brand online and are recognized as a team player within your organization.
The dollars that make "sense" here is that in the long run, your two cents will add up to dollars eventually.