Cyworld has become the dominant social networking site in South Korea, where up to 90 percent of those under 20 are believed to be Cyworld members. It now wants to expand its influence elsewhere, starting by taking on MySpace in the U.S.

Cyworld says it can replicate its Korean success based on research that shows most social-network members spend time on two or more sites, the Financial Times reports. "There is a site for the real you, a rite of passage site that you would join during a particular phase of your life, and the fun, hot, new trend site," Michael Streefland, director of marketing for Cyworld, says.

Cyworld positions itself as the site that appeals to the "real you," therefore users would remain members for years - whereas, it says, MySpace's appeal will be fleeting and short-lived.

But the massive number of MySpace users will help the site maintain its dominance, according to cofounder Chris DeWolfe. "In social networking, there is a huge advantage to have scale," he says. "You can find almost anyone on MySpace and the more time that has been invested in the site, the more locked in people are."