It's the bargain that underpins much of the social web. Twitter gives us 140 characters worth of storage and a killer API, and we fill it up with our latest thoughts and experiences. Foursquare gives us a nice way of converting GPS locations to actual intuitive locations, and we give it the scoop on where we hang out. Facebook gives us a way to connect with friends, and we tell it who we know and what we have to say to them.
This bargain amounts to the world's most ambitious marriage of public and private value creation. On the one hand you've got private companies trying to monetize their social networks and web apps, generating at least enough revenue to keep the lights on. And on the other hand you've got individuals who voluntarily engage in the social production of common value: