-By Barry Janoff

It might not all be attributed to Michael Phelps, but the eight-time gold medal winning swimmer is one of the big reasons that the 2008 Summer Olympics has become one of the biggest Internet and viral hits in sports history.

NBCOlympics.com on MSN has set records for uniques, page views and streams. It attracts an average of more than six million users daily, who stay close to 15 minutes per visit and spend 20 minutes when consuming video, according to NBC. That's good news for such advertisers on the site, which include Visa, ExxonMobil, McDonald's and Coca-Cola.

In addition, millions of visits have been made through NBCOlympics.com's mobile WAP and other VOD offerings. Since the start of the Beijing Games, NBCOlympics.com on MSN has ranked No. 1 in the sports category based on share of page views, according to Hitwise.

In all, about 2,200 hours of video will be streamed live on the Internet at NBCOlympics.com before the Games end on Aug. 24. Phelp's profile is tops in visits among all athletes at NBCOlympics.com; the most popular sports are gymnastics, swimming, basketball and beach volleyball.

"These record numbers validate our multiplatform strategy. They drive viewers to share in the Olympic experience on network television in record numbers," Gary Zenkel, president, NBC Olympics, said in a statement. "And as a result of this unprecedented digital effort, consumers have a destination to watch thousands of hours of video and relive the great moments of these Olympics."

Meanwhile, Beijing2008.cn, the official Web site of the Beijing games, is getting nearly 930,000 visits per day, with traffic exceeding one million unique visitors on several days, according to Nielsen Online, New York. (Nielsen Online and Brandweek are divisions of The Nielsen Co.)

"The Internet has removed barriers related to international time zones, as fans have 24/7 access to updated Olympics content and video," Jon Gibs, vice president of media analytics at Nielsen Online, said in a statement. "Local, regional and global Web sites are benefiting, and with English, French, Spanish and Chinese versions, Beijing2008.cn is a popular destination for Internet users around the world."

Perkins Millers, svp-media at NBC Sports and Olympics, told The Washington Post: "The biggest challenge was to push viewers to the mobile platform. We have half a million unique visitors everyday on mobile, about half of which are accessing mobile for the first time. We see significant growth. We basically doubled our uniques from the day of the opening ceremonies [Aug. 8] to [Aug. 16]."

"NBC Universal's coverage of this year's Summer Games is raising the bar for live event streaming," Brick Eksten, president at Digital Rapids, Markham, Ontario, Canada, which has provided technology being used by NBC, said in a statement. "From the volume of live streams and the massive amount of on-demand content to the quality of the end-user experience-everything about this initiative is changing how content consumers will look at live event coverage from this point forward."