Margin is the amount of money you make on each incremental sale or unit of revenue before factoring in the "fixed costs" of your business. Fixed costs would be things like the rent on your office, your administrative team, and the people who do your accounting/bookeeping work for you. The key concept to wrap your head around is some costs rise and fall based on how much revenue you have and some costs are fixed and are the "cost of keeping the doors open."
(Full Post: http://www.avc.com/a_vc/2011/04/margins.html)
Fred Wilson has been a venture capitalist since 1987. He currently is a managing partner at Union Square Ventures and also founded Flatiron Partners. Fred has a Bachelors degree in Mechanical Engineering from MIT and an MBA from The Wharton School of Business at the University of Pennsylvania. Fred is married with three kids and lives in New York City.