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.