NPR had a great article about how otaku or nerd culture is driving economic growth:

Take 24-year-old Kai. Sengoku Basara is her favorite computer game. An office worker by day, Kai spends her weekends dressed up as a 16th-century samurai, Chosokabe Motochika. Her chest is bound flat. She wears a gray wig, armored cuffs, high black boots, a red satin jacket and a red eye patch over one eye. Other women, all dressed as computer-game versions of samurai, surround her. "I don't want to be a man," she says, "I just like cosplay" -- short for costume play.

"I'm a nerd. This is Japan's new culture. To me, it's just one of the ways of showing your creativity," Kai says.

Kai is part of a new Japanese tribe -- the otaku, or nerd. Once the target of playground insults, otaku are now becoming an economic force to be reckoned with. Japan's nerds are out and proud.

Almost 200,000 people trekked out to a suburban convention center on their annual pilgrimage to the game show. Many dressed in elaborate hand-sewn costumes. All devote time -- and money -- to their passion.

The otaku market generated an estimated $4 billion in 2004, says Ai Ohara of the Nomura Research Institute, which has studied the otaku phenomenon.

And the Tokyo district of Akihabara is proof of geek spending power. Here, computer-game theme songs waft out of shops piled high with gadgets in an exuberant celebration of geekdom. Indeed, Japan's nerds, with their exacting demands, are driving consumer trends.

Interestingly, the article also goes into the dark side of Japanese nerd culture: that it is profoundly misogynistic. Otaku culture tends to depict women as sexual objects, and that is about it. Anyway, the article is available for reading or listening.