Call it an inadvertent publishing strategy.

In August 2000, Fred Gallagher, an architect and longtime fan of Japanese animation and comics, along with Rodney Gaston, his computer gaming buddy, began posting an online comic strip, "Megatokyo," as a lark. Published three times a week, the strip follows the misadventures of Piro, an introspective anime/manga fan strangely reminiscent of Fred, and Largo, a slightly deranged hardcore computer gamer much like Rodney. The two are stranded in Tokyo, flat broke after a spur-of-the-moment flight to Japan and an anime, gaming and manga spending spree.

Almost immediately, www.megatokyo.com caught the attention of the growing numbers of American "Otaku"—super fans of anime/manga—who spread the word about the site through e-mail, message boards and Internet chat. Within six months, Megatokyo.com was attracting 20,000 to 50,000 readers a day, and steadily selling related t-shirts, hoodies and blankets.

In January, when the first of three trade paperback compilations of the strip, MegaTokyo: Volume 1, became available, it sold out of its 11,000-copy first printing in less than a month and returned to press for 11,000 more—a remarkable performance for a beginning cartoonist. I.C. Entertainment, a small but fast-growing publisher of manga graphic novels and periodicals based in Fredericksburg, Va., sold about half of the books through their Web site, and the remaining copies through multimedia distributor Diamond, which handles the book trade, comics stores and other outlets.

Gallagher's second volume, Megatokyo 2: Do You Want Save Before You Quit, is scheduled for publication in March with a first printing of 22,000 copies. By comparison, top-selling manga titles from leading manga publisher Viz Communications have sold close to 100,000 copies in trade paperback, while several titles from comics publisher Dark Horse sell in the 40,000—50,00-copy range.

While manga and anime are surging in popularity among U.S. readers, Kei Blue, I.C.E.'s marketing, sales and promotional director, emphasized that American manga—comics produced by Americans in the Japanese visual style—are also gaining acceptance. I.C.E. also publishes AmeriManga magazine, which features new work by Americans. "It used to be that if you drew manga and weren't Japanese, fans would call you a poser," Blue explained. "But that's changed."

Gallagher, who draws and writes the strip, never really wanted to undertake a comic in the first place, though he gave in to prodding by Gaston. By the time he and Gaston later split "amicably," the strip had morphed into the story of an evolving cartoonist, and how his four-panel gag had become a quirky and amusing confessional narrative. Gallagher continued to produce "Megatokyo" alone, and to develop his supportive online community of devoted fans. "It's a fantastic way to reach a lot of people very cheaply," he said. "In the U.S., people pooh-pooh comics, like they're only for kids," he added, "but manga is a visual language. It's an effort to communicate something fresh."

In 1997, I.C.E. began publishing six titles a year, with a handful more appearing under an erotica imprint, Sexy Fruit Publications. This year, I.C.E. will publish 20 to 25 multivolume titles, amounting to about 70 books. When Blue took over I.C.E.'s marketing and sales about a year ago, "everything was too male oriented," she said. "Jacket covers showed a lot of skin, even if the book wasn't erotic." Since the cover art was changed, sales have doubled for many I.C.E. titles, she said.