It's a given that the "American Idol" franchise is valuable — but no one guessed its worth to be a staggering $2.5 billion.

That's the price tag slapped on the franchise by Advertising Age, the industry trade magazine.

It reached that estimate by adding up "Idol's" ad dollars ($500 million), sponsorship packages ($30 million to $50 million), music sales and live tours.

And that $2.5 billion figure doesn't even include the "Idol" chocolate bars, ice cream, Monopoly games and even an "Idol" theme park — all of which are being considered by the producers of the Fox reality show.

Fremantle Media, which holds the rights to "Idol," is also expanding the show by streaming it on americanidol.com after it airs each week — enabling even more advertisers to join the party.

The talent show returns for Season Six next week. Last season's "Idol" finale averaged over 36 million viewers.

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