LOS ANGELES (Reuters) - Fox television this week faced an uncomfortable future when the two biggest stars on its No. 1-rated show "American Idol" openly discussed leaving, which experts said could send viewership plummeting in future seasons.
Paula Abdul, whose quirky behavior has been a hot topic for years, told ABC News program "Nightline" that her contract ends after this season. And acid-tongued Simon Cowell, whom critics call the show's real star, gave several interviews in which he contemplated an exit when his deal ends next year.
"You take out one person like Paula or Simon, (and) you're affecting every other player in this grid," said Time magazine television critic James Poniewozik. "They're a family, a dysfunctional family, and it's tough to mess with that."
At risk for the Fox Broadcasting Co., which is owned by Rupert Murdoch's News Corp are millions of dollars in annual advertising revenue that would be lost if viewers tune out following a departure by Cowell or Abdul.
The pair are the most talked-about judges on the four-person panel that critiques performances of pop star wannabes competing to be the next "American Idol" and win a recording contract. They are joined by Randy Jackson and new judge Kara DioGuardi, as well as show host Ryan Seacrest.
This week, Cowell told the New York Times that when he agreed to his contract through next season, it felt like it would be his last, and he said in The Hollywood Reporter that if "Idol" dropped from No. 1, he would want to leave.
But doing so would likely be a big let-down for fans of the celebrity judge who earns an estimated $36 million a season by often heaping criticism on the program's pop star wannabes.
"He's the villain that people like to cheer against, and also I think people don't give him enough credit for this, he's actually also a really good critic," Poniewozik said.
Fortunately for Fox, the show has retained its lofty title as No. 1 on U.S. airwaves despite a slip in its audience size that could be tied to lower viewership for TV shows overall.
Now in its eighth season, "Idol" has seen its audience size decrease by about 8 percent compared to last year, and it is averaging about 26.3 million viewers per show, Fox said.
Still, it retains a 68 percent ratings lead among viewers 18 to 49 years-old, a key group that advertisers covet, over its nearest competitor, ABC sitcom "Desperate Housewives."
"'Idol' at the moment is the most dominant it has ever been," said Mike Darnell, president of alternative programing at Fox Broadcasting.
When asked about the show's prospects if Cowell or Abdul were to leave, Darnell said only that he hoped they would not.
"It is our hope and my personal wish that both of them stay for as long as the show is on," Darnell said.
Industry experts, however, are more forthcoming.
"Simon Cowell, if he left the show after next season, there would be a much bigger drop-off in terms of viewing; he's really the focal point," said Brad Adgate, a vice president at advertising agency Horizon Media.
The loss of Abdul would be a blow, too, as critics say she is crucial, if only for her often unpredictable behavior.
"Paula is a liability for any number of reasons people talk about, just the sort of crazy, scatterbrained responses she gives during the judges' criticism," Poniewozik said.
"But that's 'American Idol,' the things people complain about are a big chunk of the reason the audience watches."
Reporting by Alex Dobuzinskis: Editing by Bob Tourtellotte and Eric Walsh