(FORTUNE Magazine) – Ask any parent--if you tell kids what to do, they're sure to do the exact opposite. Tylenol seems to have read that child-rearing chapter, because lately it has been acting like the coolest parent on the block. The pain pill's maker has launched a marketing campaign aimed at young people that has an unusual characteristic: It makes no suggestion--none at all--that they should buy Tylenol.

Since last summer, Tylenol's maker, a unit of Johnson & Johnson called McNeil Consumer & Specialty Pharmaceuticals, has spent $2.5 million to fund events in fringe subcultures populated by 18-to 34-year-olds--skateboarding competitions, breakdancing contests, snowboarding exhibitions, and the like. The company doesn't put its name on the events or push freebie pills. That wouldn't be cool. Instead it gives money to organizers and key participants--people it calls "pain partners."

Pain partners? Well, think about it. This is the generation that gets pierced in unimaginable places. It is glued to TV shows in which people endure flesh-eating worms (Fear Factor) or light themselves on fire and jump out of buildings naked (Jackass). It made extreme sports mainstream. For the nation's largest pain-reliever company, all this presents an unexpected problem: The single most sought-after demographic in marketing, 18-to 34-year-olds, actually thinks pain is cool.

"They wear it as a badge," says Faith Popcorn, the branding guru who runs Faith Popcorn's BrainReserve, a New York marketing company hired by Tylenol. She spent six months interviewing 6,000 18-to 34-year-olds--from pierced receptionists to college kids boasting migraines--on perceptions of pain, and reported that they have a consistent masochistic streak.

Tylenol's numbers underscore her point. Each year 10.2% of 18-to 34-year-olds who use Tylenol are switching away from it, three times the switching rate of any other age group. (They're opting instead to tough it out, switching to rival brands or using herbal remedies or you can probably guess what else.) Tylenol's 20.3% market share and $850 million in annual sales are sustained by adding line extensions like mint-flavored Tylenol Cool Caplets and special versions for baby-boomers like Tylenol Arthritis Pain and Tylenol PM. But sales of the core product are slipping. McNeil president Bill McComb says wistfully: "If you lock in with an 18-to 28-year-old, I can assure you a lifetime user."

There was another bit of bad news: This key demographic is virtually immune to traditional advertising, thanks to TiVo, which lets consumers edit out commercials, and iPods, which lets them tune out radio sponsorships. To gain Tylenol respect among jaded youth, McNeil opted for a super-low-key approach.

Tylenol's campaign managers are clear with their "pain partners" and event coordinators that they don't want the product pushed. Even the brand's name is absent from the campaign, which is entitled "Ouch!"

"Wow, totally random and supercool," says a nose-ringed twentysomething, picking up a white box emblazoned with "Great pain leads to great art" as she walks out of the New York Underground Film Festival's audio-visual event in Williamsburg, Brooklyn. She sifts through an ironic goody bag for artsy kids: a mini Etch A Sketch, an aromatherapy candle, a CD with soothing music, and a sketchbook--all emblazoned with "Ouch!" The small red "Tylenol" on the corner of the box is the only hint that the brand is sponsoring the music videos projected on a makeshift screen in the dank nightclub.

Outside, Tobin Yelland, an urban photojournalist with a digital videocamera, interviews smoking hipsters. Responding to his call for "pain stories," they gruesomely recount Rollerblading accidents, split fingernails from art projects, and head-splitting all-nighters. Yelland doesn't volunteer that he's a Tylenol pain partner.

Over in East Los Angeles, at the ninth annual "B-Boy Summit," Tylenol is also quietly hanging out. Pain partner Asia One, a muscular 32-year-old in camouflage pants and a blue skin-tight tank, is a B-Girl (breakdancer to you squares), a key player in this hip-hop subculture offshoot. She is known for a head-spinning move that has earned her a quarter-sized bald spot. She emcees the breakdancing contests in a parking lot. Members of the multiethnic crowd shoot pictures of the dancers against a graffiti-covered canvas. They're using disposable cameras emblazoned with "Ouch!" that the company is handing out at a little table off to the side.

In New York City's first indoor skateboarding area in Greenpoint, Brooklyn, Tylenol downshifts to a no-key approach. There's not a single "Ouch!" in the unheated, crumbling brick industrial space that holds an amoeba-shaped skateboard bowl Tylenol helped fund. (You'd think the company would worry about lawsuits for backing a locale reached only by going down a dark alley, over broken bottles, and under an unmarked, half-open garage door.) Swishing around the undulating sanded wood are Buddy Nichols and Rick Charnowski, pro skateboarders cum indie filmmakers, who shoot 8mm movies of the underground skateboard scene and are Tylenol pain partners. "Awesome," says Nichols to the bowl's creator and gate-keeper, Dave Mims, another pain partner who owns a skateboard shop in Manhattan's grungy East Village. He charges about 20 of his insider friends a fee for a key to the space but always welcomes hard-core out-of-town skateboarders. He doesn't advertise that Tylenol pitched in.

Yet the three unshaven thirtysomethings refer to the raw space as the Tylenol Bowl. It doesn't make sense. There's no sign of the company, nor was there any formal announcement or press release indicating a connection. Charnowski reports that the brand's unannounced affiliation is paying off. Skateboard magazines have made a number of unsolicited references to the Tylenol Bowl and skateboarders in Seattle and Denver have asked Nichols and Charnowski about the Tylenol Bowl without knowing that they are pain partners.

It's implausible, but Tylenol's calculating whisper has been heard. It's in a song by rocker Ben Kweller, which went on sale this summer in Apple's online music store. Called "Tylenol," it begins:

I need some Tylenol Give me some Tylenol To kill that headache you gave me.

And earlier this year, Saturday Night Live did a 60-second fake ad for an imaginary product for X-Games addicts: Tylenol Extreme, designed to "relieve testicular trauma." Classic SNL mockery, rife with raunchy humor, the spot was twice as long as a commercial and mentioned the product seven times. That kind of exposure is priceless: It can't be TiVoed out.

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