HOLLYWOOD — Everyone knows who Hannah Montana is. But perhaps only kids know she's been unseated as TV's reigning tween queen by one Carly Shay.

Carly, the plucky 15-year-old star of the Nickelodeon comedy "iCarly," quietly overtook Disney Channel's "Hannah Montana" — and this year, "American Idol" — in the ratings race for young audiences.

Miranda Cosgrove, who plays Carly, is still a name that draws quizzical looks while Miley Cyrus sells out movie theaters and concert arenas. Nor is Cosgrove the whirlwind of controversy that Cyrus has been. Recently, Cosgrove posted to her Twitter page: "Just finished 5 more hours of math. At least this afternoon was fun! My first real driving lesson!" — a far cry from Cyrus' recent bio (dating a 20-year-old, a Jonas brother, and posing provocatively for Vanity Fair).

And yet, in its second season, "iCarly," which follows the misadventures of three friends who produce a Web show about, well, nothing in particular, has grown into TV's No. 1 series among kids (ages 2 to 11) and tweens (ages 9 to 14), drawing an average 5.6 total million viewers to new episodes.

ONLINE ADVANTAGE

So how did Carly do it? Unlike her scandal-attracting peers, she has the Web working with her instead of against her.

By design, "iCarly" is the only kids' show plugged seamlessly into the online world, a playing field populated by blurbs of random, often outrageous comedy. Series creator Dan Schneider has been savvy enough to plot the "iCarly" Web segments as randomly as any teen would a YouTube channel.

During the show-within-a-show webcasts, which the characters film in Carly's attic, Carly and her friend Sam (Jennette McCurdy) demonstrate making chicken soup in a toilet. They create trailers spoofing teen movies. They morph Carly's head onto a picture of Sam's rabid cat. They improvise short sketches with names like "The Cowboy With a Mustache and the Idiot Farm Girl Who Thought the Mustache Was a Squirrel."

"When I pitched the show, (Nickelodeon executives) asked, 'What's the Web show?' I said, 'Whatever we want,' " Schneider said.

"iCarly" is his fourth live-action show for the network; he previously created the hits "Zoey 101," "Drake & Josh" and "The Amanda Show." It's frantic, silly and never predictable.

"I don't know who else besides us could say they've run over a microwave filled with toothpaste in a monster truck," McCurdy said.

Schneider also has been savvy about what the kids are watching and sharing online. In February, "iCarly" devoted an entire episode to viral video star Lucas Cruikshank, who plays Fred, a hyper 6-year-old with temper problems, on his YouTube video channel, the site's most subscribed-to feed.

"I go online a lot, and I read stuff all the time from fans saying they love the weird stuff, the stuff that doesn't belong anywhere or make any sense," Schneider said.

To that end, he keeps the www.iCarly.com Web site stocked with online-exclusive videos to keep fans buzzing between new episodes. And, along with his actors, he is big on Twitter. Over the weekend, he posted a dozen pictures of Cosgrove getting her first driving lesson.

Which is not to say "iCarly" is simply a string of Web-inspired sketches and gags. Outside of her Web hosting duties, Carly is an overachiever in school, kind of neurotic and usually more mature than her older brother, Spencer (Jerry Trainor), who raises her while their dad is (permanently) stationed on a submarine in Europe. Sam is her brash, school-hating best friend and Freddie (Nathan Kress) is their nerdy-cool Web show producer. Together they get into trouble while producing popular Web TV.

GOING FOR BIG FUNNY

Further separating it from your average kids' sitcom, the series talks up to its audience, often appearing to forego lessons learned in favor of laughs. In the season 2 premiere, Carly and Sam decide to date the same boy, and as they fight over him toward the end of the half-hour, he stumbles backward, falling eight floors down an elevator shaft and winds up in a full body cast. It ends the squabbling — and the episode.

"There's no resolution and I love that. And let me tell you, it took me a long time to win those battles (with the network)," Schneider said. "The sweet wrap-up scenes? Who wants to see 'em? Let's just end on big funny."

Nickelodeon and MTV Networks Kids & Family Group President Cyma Zhargami said Schneider has earned the right to get his way, having worked on the network's comedies since 1997's "Kenan & Kel." "He goes farther and farther in every episode, but as you start to understand it's just a big fat comedy, your tolerance goes up for the not-so-sappy endings. And that's fine," she said. "I like to think he's innovating, not pushing boundaries."

In spite of the show's dramatic ratings gains, and a memorable role as the know-it-all 10-year-old band manager in 2003's Jack Black comedy "School of Rock," Cosgrove is without the promotional power of the Disney empire — ABC, Hollywood Records and Walt Disney Pictures — that has made stars of Cyrus, Hilary Duff and Zac Efron.

Instead, she falls neatly into the tradition of Nickelodeon talent, which includes recent breakouts Emma Roberts and Josh Peck, teens who are now trying to build their acting careers in independent films. Cosgrove is not a glammed-up pop star; she is a mirror of the audience watching her.

Cosgrove's Carly plays well because "she's just a girl," Schneider said. "She's beautiful and cool, and she could also be your best friend."

He continued: "I don't care about getting the most coverage on the news. And I can't control that, anyway. Actually, the competition warms my heart. Because, despite Disney's massive marketing machine, they still can't overpower 'iCarly.' "

Cosgrove might not incite frenzies yet, but her own star is rising: Paramount Pictures and Nickelodeon Films are developing "How Could You Do This to Me?" a comedy about a teen trying to keep her divorced parents from reuniting — ironically (or not), a plot antithetical to Disney's 1998 remake of "The Parent Trap," starring Lindsay Lohan — as a possible vehicle for the actress.