Before long, her mysterious mug had been slapped on cash registers and school lockers from San Diego to San Francisco. It’s a technique that has been used by artist-marketers from Keith Haring to Shepard Fairy, who plastered cities with stickers of the wrestler Andre the Giant. Videogame companies such as Rockstar Games, creators of Grand Theft Auto, employ similar guerilla-marketing techniques around New York City. But Reger’s is an early example of a viral strategy. “I always have a pack of Emily stickers on me,” he says. “They’re the best form of ads.”

As Emily’s image spread in 1993, Reger moved to capitalize on her popularity. He took out ads in the backs of a couple of skateboard magazines, and hired a part-time “propagandist,” to send Emily shirts to stylists and MTV V.J.’s. That year, he also hired a friend who had been working in distribution for a streetwear company called Stoopid Clothing to grow Emily’s presence in retail, and brought on an artist friend from college who was willing to work on the cheap to help with the designs.

Reger scored national distribution in 1996, just after attending his first trade show. But he was selective about where the products went—such as the franchise Hot Topic, which fell for Emily at a show for boutique stores. By 2000, Emily shirts had landed in hipster boutiques from Haight-Ashbury in San Francisco to Newberry Street in Boston. She found fans in smart, arty girls like Kate Leth, a 17-year-old student in Nova Scotia, Canada. “She’s just a great character—more clever than cynical, more mischievous than evil,” Leth says. “She reminded me a lot of myself when I was in junior high and early high school.”

By 2003, Reger’s company had grown to 30 employees, and revenues had gone from $10,000 to $6 million. He was faced with the formidable challenge of turning down lucrative opportunities—including a cell phone endorsement in Japan, which could have turned Emily into the next Hello Kitty; a television series with Disney; and distribution in Target. “I’m very careful about my strategic partnerships,” he says. When he thumbed through his own library, he found that his favorite art books—on subjects ranging from Pop Art to 1950s logos—came from Chronicle Books.

Chronicle has since sold over 500,000 units of Emily products, from notepads to diaries. The product line is based on one simple precept: “You never see her doing something that isn’t true to her identity,” says Chronicle executive editor Mikyla Bruder. Instead of paling around with Britney wannabes, Emily hangs with four black cats.

While comics and little black journals are natural fits for Emily, the leap to the silver screen is riskier. It’s a move Reger isn’t taking lightly. For years, Hollywood producers had been pitching him on an Emily movie—and scaring him away. “They wanted to make her 17 and have her start dating [other kids],” Reger says. Romance, he believes, is antithetical to Emily’s role as the perpetual 13-year-old loner. It wasn’t until he sat down with two movie geeks at Fox that he found partners whom he felt understood both him and his brand. “Instead of being motivated by hype,” he says, “they asked me what I wanted to do.”

The film, Reger says, will evolve Emily’s story in a combination of live action and animation. Though no actors or other details have been announced, Emily will stay 13, just as Reger wanted. But others are bracing for Emily’s migration into the big time. “The impact of film is always a concern,” says Bruder. “The risk is that people will say ‘Oh, Emily, she’s so mass now.’ This is an audience that likes to discover things.”

Reger plans to keep that sense of discovery alive by scrutinizing Emily’s progression as closely as ever. He’s exploring two new mediums for Emily: videogames and music. No matter where she winds up, he says, he’ll approach each venture with the same strategy that got him where he is today. It goes back to the punk songs that inspired him as a kid. “They said ‘think for yourself and question authority,’” he says. “I question everything.”