Good technology has value, but leading social networks require "network effects." Facebook is infinitely more valuable because all your friends are on it.
Facebook has leveraged this "critical mass" of users to stay ahead of new rivals, too. Why visit Twitter, you may ask, when Facebook has continually extended its feature set to keep up with its less popular competitor?
The story of social networks is in fact a story about network effects: How can a service reach a point at which there are enough users and content to be useful?
"The Internet, which many feared would draw viewers away from television, appears to be having exactly the opposite effect - at least when it comes to coverage of major events.
Brian Stelter writes in The Times that TV executives have noticed big spikes in viewership of the Olympics, the Super Bowl, the Grammys and other special events that some of them trace to the effect of social networking sites."