There is, presumably, a limited supply of reputation and attention in the world at any point in time. These are the new scarcities--and the world of free exists mostly to acquire these valuable assets for the sake of a business model to be identified later. Free shifts the economy from a focus on only that which can be quantified in dollars and cents to a more realistic accounting of all the things we truly value today.

From Free! Why $0.00 is the Future of Business on Wired.com.