Whoever maximizes the ratio $$ \frac{\text{People Reached}}{\text{Questions Answered}} $$ must have an uncanny sense for which questions are going to be heavily viewed and worth answering. In some sense, they use the site most efficiently (if your goal is to reach people). Who is this person? What is their "impact factor"?
I wonder if one of the database wizards would be interested enough in this silly query to code it up. Perhaps the answer turns out to be uninteresting because someone created an account just to answer a single popular question, in which case maybe there should be a requirement that the winner has answered at least five questions or something. A related question might be to replace "People Reached" with "Reputation".