The critical component in social networking is the removal of time as a constraint. In the real world, according to research by myself and others, we devote 40 percent of our limited social time each week to the five most important people we know, who represent just 3 percent of our social world and a trivially small proportion of all the people alive today. Since the time invested in a relationship determines its quality, having more than five best friends is impossible when we interact face to face, one person at a time.
Instant messaging and social networking claim to solve that problem by allowing us to talk to as many people as we like, all at the same time. Like the proverbial lighthouse blinking on the horizon, our messages fan out into the dark night to every passing ship within reach of an Internet connection. We can broadcast, literally, to the world.