Resuscitating 'Idol,' and idols

In a statement released the day her hiring was announced, Carey made the job sound like a mission of mercy. "As a singer, songwriter and producer, it's going to be fun and rewarding to help find new talent and give back to American Idol," she said.

But what's in it for the Grammy-laden singer with the supersonic range (besides a multimillion-dollar salary for five months of part-time work)?

To answer that, you have to go a little deeper into the statement:

"I am currently in the studio working on my new album and its first single, 'Triumphant,' which will be out early next month."

There you have a better clue to Carey's motivation. As Idol heads into its 12th season, the show has flipped its original mandate.

It has become less about finding unknown singing talent and more about providing a promotional platform for its famous, if faded, celebrity judges.

You'll hear a lot in coming months about Mariah's being one of the most successful recording artists of all time, having sold more than 200 million albums worldwide.

But bear in mind, she peaked in the 1990s. While still commercially viable, at 42, she's no longer the platinum princess she once was.

Carey is presumably hoping that Idol will provide her, as it did her immediate predecessors Steven Tyler and Jennifer Lopez, the kind of buzz you can't buy or manufacture.

In other words, at this point you take the Idol gig with the expectation that it will give you a career boost that will quickly make you too busy to be an Idol judge.

The networks have adopted a competitive policy of shelling out megabucks for celebrity judges on their reality talent shows.

Christina Aguilera will pull down $10 million for the third season of The Voice; Britney Spears is reportedly making $16 million for joining The X Factor panel.

The idea is that big names equal big ratings. But does this equation add up?