Never mind websites. Forget page views. They're so 2006. This was the year of Facebook. The social site, started in 2004 to organize college communities, was finally opened to the rest of us, and in the spring it was discovered en masse by media wonks (like me), who forced acquaintances into joining, using the evangelistic fervor of recent cult converts.

Then, in May, Facebook opened up to developers, who now were able to add applications to the service; already they've built 5,000. And in October, Microsoft beat Google to invest in the company at a valuation of $15 billion.

Worth it? I'd say yes. Facebook has 50 million active users (each worth $300, according to Microsoft, as opposed to $500 a year for a newspaper reader, according to Deutsche Bank). They are joined by 200,000 more daily, all of whom spend an average of 20 minutes every day inside.