The popularity of social networking worldwide, as reflected in the study, underlines the reasoning for recent global expansions undertaken by such sites as YouTube and MySpace.

While 20% of regular Internet users worldwide had visited a social networking site in the previous 30 days, the figure was 55% in Korea and 24% in the U.S., Ipsos said.

Social networking's popularity in South Korea was largely attributed to Cyworld, which counts 18 million South Koreans - or roughly 30% of the country's entire population - as members.

Ipsos said that at least two-thirds of all Internet users worldwide who have ever visited social networking sites had done so in the past 30 days, showing that they have generated a captive audience "even among lesser developed markets," according to Brian Cruikshank, executive vice president and managing director of Ipsos' Technology & Communications practice. Cruikshank said the numbers are particularly significant "when one considers the various ways for users to interact with others using these sites, such as online chat, text messaging, email, video, voice chat, file sharing, blogging, discussion groups, and so on."

The research firm also found online video to be increasing worldwide, although not as widely as social networking. The growth, Ipsos found, is most pronounced in developed markets. "Where homes are saturated with televisions and DVD players, video content is a predominant part of consumers' daily lives," said Cruikshank, and "the PC will begin to really assert itself as a 'second screen' within the household."

In the U.S., Ipsos reported, over one-third (36%) of recent Internet users responding to its survey have watched a TV show or other video stream online, up from 28% a year earlier, and three-quarters of them had done so in the previous 30 days. Worldwide, the figure was 34%, up from 31% a year earlier.

While online video use continues to rise, Ipsos found that online music, the previous digital lifestyle driver, has stopped growing. According to the study, 51% of Internet users worldwide played streaming music or radio, down from 52% a year earlier; 43% downloaded a music file, down from 44%, and 41% burned or copied music onto CDs, unchanged.

Ipsos Insights surveyed 6,553 adults in November and December, 2006, in urban Brazil, Canada, urban China, France, Germany, urban India, Japan, urban Mexico, urban Russia, South Korea, the U.K. and the U.S.

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