News Corp.'s ( NWS) Fox is using its popular MySpace.com site to challenge Yahoo!'s ( YHOO) supremacy in fantasy football.

MySpace users now see a promotion for the game on the FoxSports.com site. It boasts free features such as live scoring and statistics, which Yahoo! players have to pay a fee to receive. It also allows MySpace users to add sports headlines to their profiles, or their personalized Web pages that make up the MySpace site.

It's unclear how much impact the campaign has had on fantasy football signups, which began in earnest ahead of Thursday's kickoff of the NFL season. Nonetheless, Fox is optimistic that it's gaining ground in attracting users.

"The numbers exceeded our internal goals by quite a large margin," said Brian Grey, senior vice president and general manager for Fox Interactive Media, in an interview. "We're ecstatic."

Grey, who joined Fox last year from Yahoo!, where he oversaw that company's fantasy sports games, declined to be more specific.

Fantasy football is just the latest example of how New York-based Fox is using MySpace to promote its other businesses. Fox also announced plans to provide a preview of the season premiere of "The Simpsons" on MySpace and other Web sites that are part of its Fox Interactive Media unit. Episodes of the Fox cartoon "American Dad" and FX cable comedy "It's Always Sunny in Philadelphia" can also be streamed through MySpace. Burger King ( BKC) is sponsoring both promotions.

Fantasy sports are serious business for media and Internet companies. Fantasy football, the game in which people choose teams of NFL players and are awarded points based on their performance, is one of the most popular activities on the Web. Gamers also are an attractive demographic for advertisers because they need to spend time online researching the NFL.

"It's a perfect cross-sell," says Chris Young, vice president for rich media at the online advertising company DoubleClick . "The MySpace demographic profile is playing perfectly in the fantasy football demo."

News Corp. is getting plenty of help promoting MySpace, which has yet to turn a profit. Google ( GOOG) agreed last month to pay Fox $900 million to become the search provider for the site. Google also has a right of first refusal on display advertising sold through third parties on Fox Interactive Media's network.

Though MySpace's ad sales are expected to be a modest $180 million this year, they will rise to more than $1 billion by 2010, according to an estimate by the research firm eMarketer.

Shares of News Corp., up more than 17% this year, rose about 16 cents to $19.54, on Friday.