After a customary eight-month break, "American Idol" mania starts again tonight, with the usual mix of delusional singer wannabes, publicity hogs and gems in the rough.

But for those of you who don't track every off-season "Idol" tidbit, here are a few things you may not have known about what is now America's most popular TV show, as it enters its sixth season.

"Idol" would make a great investment.

If "American Idol" were a stock on the New York Stock Exchange, it would be like Google. Ad Age this month estimated the value of the franchise at $2.5 billion. That includes $500 million a year in domestic ad sales on Fox TV, millions more in CD sales from the contestants, the hugely successful live "Idol" tour and fees from 40 "Idol" licensees. This includes everything from the PlayStation "Idol" Karaoke Revolution game to 79 million "Idol"-branded Nestlé candy bars to Dreyer's ice cream, with themed flavors such as "Drumstick Diva" and "Hollywood Cheesecake."

You can write a song for "Idol."

In past years, fans have cringed at the songs that winners and runners-up have been forced to record. Remember Carrie Underwood's "Inside My Heaven"? Or Katharine McPhee's "My Destiny"? Do you even want to? To possibly remedy that, "Idol" is holding a songwriting contest for the first time, hoping to find a tune people might be willing to listen to after the show is over.

"Idol" promises a midseason "surprise."

"Idol" executive producer Cecile Frot-Coutaz told the New York Daily News last month that there is some unspecified "huge event" midseason, something that will "blow America away." We have no clue what this may be, though it's possible the show may bring back voted-off contestants for a second chance — or finally persuade Paul McCartney to show up.

Missed the show? Check it out online — or on your cellphone.

For the first time, americanidol.com will make episodes available online in case you missed them and didn't tape them. Sponsor Cingular (soon to be AT&T) will make some performances available for cellular customers the day after it airs on Fox.

Chris Daughtry is blowing Taylor Hicks away in CD sales.

Intense rocker Chris Daughtry, who was surprisingly voted off early and came in fourth last year, is proving to be more popular than any other nonwinner of "Idol" since Season 2's Clay Aiken. In just five weeks, Daughtry's CD has sold more than 1 million copies, and his debut single, "It's Not Over," has signs of being a smash on Top 40 and rock stations. In comparison, Taylor Hicks' self-titled CD has sold a respectable 540,000 copies in three weeks, but that's well behind Daughtry's pace. It's not helping that Hicks' record label has yet to release a single to radio.

The producers actually show some restraint.

Some people think "Idol" has been the king of overkill. It's not, really. "Idol" producers have fended off demands by Fox to air even more hours and kept most results shows to 30 minutes. In comparison, ABC's "Dancing With the Stars" dragged out results shows to an hour every week. And unlike "Dancing" or "Survivor," Fox restricts the show to just one cycle a year instead of two, allowing time for fans to unwind and build anticipation for the next season.

Most "Idol" contestants stay in show business.

A vast majority of the 58 former "American Idol" finalists are already asterisks in the pop culture pantheon. A few are bartending or working construction to pay the bills. But most are trying to stay in the public eye. RJ Helton, a former Cumming resident who finished fifth in 2002, has moved to New York and makes appearances judging talent competitions. Lawrenceville's EJay Day, who was the first finalist eliminated from the first "Idol" competition in 2002, entertains on cruise ships. And Atlantan Vanessa Olivarez, who finished 12th in the second season, is lead singer of the local country group South 70.

Simon & Co. see only a small fraction of those who try out.

"Idol" likes to brag that 100,000 people try out each year. But the producers cull out most of them, so judges Randy Jackson, Simon Cowell and Paula Abdul only see the best — or the worst. Jackson said last week they listen to about 400 contestants per city, or 2,800 total. So the chances of getting a couple of minutes with the trio is less than 3 percent. And the odds of making it on air are even less.

Average TV audience for 'American Idol'

• Season 1 performance shows: 12.1 million

• Season 1 results shows: 13.6 million

• Season 2 performance shows: 21.6 million

• Season 2 results shows: 21.9 million

• Season 3 performance shows: 25.7 million

• Season 3 results shows: 24.3 million

• Season 4 performance shows: 27.3 million

• Season 4 results shows: 26.1 million

• Season 5 performance shows: 31 million

• Season 5 results shows: 30 million

SOURCE: Nielsen SoundScan

Sample theme weeks from each season:

• Season 1: Big band, '70s songs

• Season 2: Disco, Billy Joel songs

• Season 3: Motown, Elton John songs

• Season 4: Billboard No. 1 hits, musicals

• Season 5: Country songs, Elvis songs

Source: "American Idol"