From Neil Gaiman’s commencement speech at The University of the Arts (http://www.uarts.edu/neil-gaiman-keynote-address).
People keep working, in a freelance world, and more and more of today’s world is freelance, because their work is good, and because they are easy to get along with, and because they deliver the work on time. And you don’t even need all three. Two out of three is fine. People will tolerate how unpleasant you are if your work is good and you deliver it on time. They’ll forgive the lateness of the work if it’s good, and if they like you. And you don’t have to be as good as the others if you’re on time and it’s always a pleasure to hear from you.