Virtual communities – associations that use the Internet as an organizational base – have developed into a mass phenomenon.

Facebook, not a single virtual community but rather a (commercial) platform for many different virtual networks, has almost 70 million active users across the world. Along with all the private friendship networks, Facebook also accommodates some 55,000 networks formed by communities in a region, profession, workplace or school. Nearly half of all Facebook users visit the site at least once a day.
Facebook's revenues for 2007 were about USD 150 million, with an estimated profit of USD 30 million. Judging from Microsoft's purchase of 1.6 percent of Facebook for USD 240 million in October 2007, the total value of the company was estimated, at least by Microsoft, at around USD 15 billion, or 500 times its annual profit.

Blizzard, the company behind the online game World of Warcraft (WoW), announced that it now had more than 10 mill...