Star power can't lift 'American Idol,' but it's still a win for Fox

The producers at "American Idol" wanted to shore up a dramatic slide in ratings for the show's newest season, so they added three star judges and even allowed viewers to vote online for favorites up to 50 times simultaneously.

The changes for the 12th season didn't help. Ratings have plummeted by double digits for the second year in a row, down this season by 18%, to 15.8 million total viewers, according to Nielsen. In its fifth season in 2006, "Idol's" average audience was more than twice as large. And the declines are just as bad among viewers ages 18 to 49, the demographic that advertisers crave most.

"'Idol's' sort of run its life as being at the top of the heap," said Steve Smith, a partner at the Dallas-based ad agency Firehouse.

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Analysts blame the decline on a variety of factors, including audiences tiring of the concept after more than a decade, a constantly rotating panel of judges and a glut of rival singing shows.

Whatever the reasons, the comedown has serious implications for Fox.

For eight straight seasons, the News Corp.-owned network has been No. 1 with viewers 18 to 49, a feat almost entirely attributable to "Idol." For advertisers, "Idol" became the most expens! ive on TV, with 30-second commercials running more than $700,000 during Season 7. Even with ratings falling last year, the show grossed more than $800 million in ad revenue alone, according to Kantar Media.

Perhaps more important, for the past decade "Idol" has proved that, in the face of stiff competition from online media and cable niche series, broadcasters can still gather a weekly audience of tens of millions with the right product. It found a high-profile rival in NBC's