It looks like the cult of youth is still accepting new recruits: In Hollywood, where "old" has long equaled "out," those precocious tweens have bumped off the 18-24 crowd in the contest for most desirable demographic. They might not hold jobs, but tweens wield combined spending power of about $250 billion in the United States alone -- and that's all disposable income.

With all of those allowance dollars available for the taking, it's no wonder the entertainment industry is scrambling to discover and promote an unprecedented number of bankable young stars to open films theatrically and fill concert amphitheaters. Look no further than the 17-year-old Olsen twins and their $2 billion empire of clothing, videos and makeup, or the meteoric rise of Lindsay Lohan, star of Buena Vista's "Confessions of a Teenage Drama Queen" -- or even the cottage industry that has turned 15-year-old Hilary Duff into a TV, movie and music star, catapulting her recent debut album to No. 1 on the Billboard 200 in two weeks flat.

But while the mainstream media views tweens as a relatively recent phenomenon, another service quietly has been attracting tween converts by the hundreds of thousands for the past seven years -- and it happens to share a moniker with the leading brand in family entertainment.

Radio Disney reaches an estimated 23 million 6- to 11-year-olds, for whom it is the radio brand. Its broadcasts are heard in 58 U.S. markets -- including 18 of the top 20 -- that reach 61% of the nation. The network owns and operates 56 AM stations and seven FM stations and continues to expand its reach in North America and worldwide. Radio Disney president and general manager Jean-Paul Colaco was promoted last year specifically to accelerate expansion into South America, Central America, Europe and Asia.

"Radio is the medium of choice internationally versus television because it's so well-distributed," Colaco says. "The ability to go international with radio is a huge opportunity for the (Walt) Disney Co. but also a way for (Radio Disney) to build a business."

In the United States, Radio Disney's programming is syndicated nationally, with all music and DJ banter produced in Dallas and piped live to local stations via a 24-hour satellite feed from Disney-owned ABC Radio Networks (Radio Disney's immediate parent). Five-and-a-half minutes of every Radio Disney hour are set aside for local advertising and promotions, with station-based "promotional DJs" (usually one per station) handling public-service announcements, promos and community events.

The music can be of any genre. Although culled predominantly from the top 40 and contemporary hits radio formats, playlists also can include anything from cartoon songs to the Village People to soundtrack hits (including many from Buena Vista and Miramax films, of course). That's because the listeners "program" the music, voting for their favorite songs at RadioDisney.com or via a toll-free number that receives as many as 2 million calls a month.

It's precisely that type of interactivity that appeals to children. "We have created some very early adopters of music," says Dallas-based vp programming Robin Jones, who has overseen Radio Disney's programming since the network launched with a four-market test in November 1996. "It's something that great brands like McDonald's have known forever, that if you get people to adopt your product when they're young, they'll return to it time and time again."

Traditional radio, Jones notes, practically has ignored children age 12 and under, while Radio Disney fosters one-on-one interactive relationships with its tween audience -- whether through the telephone, live promotional events or the Internet. As part of its mission to "empower kids," a young listener's voice is heard on the air at least once every 10 minutes. "We've given them a place to go and be treated with respect and have fun in a way that's relevant to their world -- and that's not annoying to their parents," Jones says.

During an average week, 2.7 million children and 1.4 million mothers tune in to Radio Disney, an audience comparable to that of a children's cable TV network. With more than 50% of listening taking place in cars (and therefore with a presumed parent at the wheel), Radio Disney is blessed with a unique -- and captive -- dual audience.

"This is one of the unique places that you can get moms and kids together," Colaco says. "It's very difficult to get the entire family watching the same television show, but you get moms and kids in the car going to the grocery store, driving by McDonald's, going shopping for clothes -- so there's a huge opportunity to get them very close to the time that they're actually making a purchase."

Still, convincing national advertisers to invest in children's radio remains relatively challenging -- especially considering that Arbitron, which tracks the listener data on which radio ad rates are based, does not track children under 12. But Radio Disney has managed to gather a growing number of major advertisers, thanks largely to its dominance in the market.

The entity that would have been Radio Disney's closest competitor -- the Minneapolis-based Children's Broadcasting Corp.'s AAHS (pronounced "oz") radio network -- went out of business a mere eight months after Radio Disney announced its debut. (An interesting footnote: CBC sued Disney at the time -- alleging that Disney stole trade secrets and used them to launch Radio Disney -- because ABC Radio had been a marketing partner of CBC's. A federal jury awarded $20 million to CBC, but the verdict was overturned on appeal.)

In addition to advertising, sponsorships help pad Radio Disney's bottom line. In an example of corporate synergy, the stations frequently run promotions by which contest winners, for example, win trips to Los Angeles to meet the stars of Miramax's "Spy Kids" films or high-profile Buena Vista features like 2003's "Holes."

That type of "kiddie buzz" has proved attractive to family-friendly advertisers -- be they minivan manufacturers, toy and video game companies, music and department stores or consumer brands such as Kellogg's, Campbell's and Procter & Gamble. Typically, companies shell out a minimum of $250,000 in ad buys for the value-add "halo" effect of being associated with high-profile promotions.

Sources decline to reveal exactly how many of the tweens' billions are lining Radio Disney's coffers each year, but in the CBC lawsuit, the plaintiff's lawyers contended that in shared internal documents circa 1995, Disney valued the children's radio market at $116 million-$274 million in annual advertising revenue.

At a time when the music outlet's corporate parent is the subject of so much speculation -- prompted by Comcast's hostile takeover bid and the controversy surrounding longtime Disney chief Michael Eisner -- that dollar figure makes for interesting guesswork. Media analyst Drew Marcus of Los Angeles' Deutsche Bank estimates that Radio Disney accounts for less than 10% of Disney's ABC Radio revenue -- or perhaps much less. "Right now, their success is very limited, as proved by the fact that it's on AM," he says. "If it was really working well, they'd put it on FM."

Colaco seems to admit as much. "We're very small in relation to some very, very huge divisions at the company that are doing billions of dollars in revenue," he says. "But our revenue has continued to grow despite the challenges in the economy, and we are profitable."

But the value of the Radio Disney unit transcends dollars and cents. The brand has been extended to include Radio Disney Live! concert tours, "Radio Disney Jams" compilation CDs (six volumes with more than 2 million cumulative units sold), consumer products and electronics -- singing interactive dolls sold as Radio Disney Pop Dreamers -- and Hit Clips music players. Other extensions include new distribution platforms such as XM and Sirius satellite radio, digital cable and television and an "American Bandstand"-type TV show. All of that adds up to a great deal of increased exposure for Disney as a whole.

"With the core Disney brand, there are challenges reaching the upper end of that (age) range, so being able to really target and reach the tween market has been a very important realization for ourselves," Colaco says. "This (isn't) just a radio station reaching 4.5 million people every week; it is a brand."

That far-reaching impact is catching the attention of the music industry's hippest decision-makers. When it comes time to launch the next generation of stars with tween appeal, Radio Disney appears poised to be an integral part of those strategic planning sessions.

"They're responsible for a lot of success (of) Aaron Carter," says Joe Riccitelli, senior vp pop promotion at Jive Records, which represents many among the first generation of mega-artists of teen and tweendom, including Britney Spears, 'N Sync and Backstreet Boys. "I can't say that they're responsible for Britney Spears being the icon that she's become, but if you look at their playlist, 'Oops! ... I Did It Again' is still being played 30 times a week."