The first run of 10,000 books is almost sold out. Ohanian's half-baked publishing project has attracted dozens of uninvited proposals from authors. And the school in Laos, whose $32,000 goal was reached shortly after the first two book signings in San Francisco and New York, is almost constructed.

You're right if you guessed all -- or none -- of the above. "XKCD: Volume 0" is a gamble that's paying off for Munroe, a former NASA contractor who left to pursue stick-figure cartooning full-time.

What's the most stupidly ambitious aspect of " XKCD: Volume 0 ," the book based on the wildly popular yet still very underground webcomic:

"We were joking that we'd fill the entire library with XKCD books," Ohanian said on the phone from Hong Kong, a stop on his way to a conference in India. "Those kids, by becoming literate, will one day buy more books. So it's a long-term investment," he said dryly.

XKCD already had a direct line to its core audience . Millions check into XKCD.com each month for a laugh at the latest comic, many returning several times per week. All Munroe had to do was post an announcement saying, "There's XKCD stuff in the store," and fans rushed down the digital aisles on the book's Sept. 15 release.

"He didn't need any help marketing," Ohanian said. "And he didn't need that much help distributing." Ohanian should know. XKCD handles Reddit's merchandise distribution.

It was only natural that XKCD go a nontraditional route for publishing. After all, there's no way the comic could have survived the traditional syndicated comic lifestyle, Munroe said. The XKCD philosophy is to cater to a niche audience and then let members of that audience proliferate the comics among their friends.

"The Internet has completely changed how you can do this kind of art," Munroe said. "I've read a couple of books about what it's like to do art in the syndicate. ... It sounds really miserable."

Aside from frequent fan requests, there was no guarantee that XKCD readers would buy a neatly bound, dead-tree version of the black-and-white graphics. XKCD's audience looks uncannily like the ones that rarely pay for movies or music, downloading copyrighted content by the hundreds.

But as Cory Doctorow and Wil Wheaton have also shown, if this new generation of consumers cares about the property, they'll pay for it. Especially in book form.

Maybe that's a topic to explore in future XKCD comics or in "XKCD: Volume 1," which Ohanian believes is on Munroe's road map.

But for now, XKCD's math geeks still have to solve the book's puzzle. In the meantime, Munroe, an engineer at heart, is constructing underwater radio-controlled robots. No joke.

-- Mark Milian

Photos: XKCD cartoonist Randall Munroe signing books at Anybots Inc. in Mountain View, Calif. Credit: Alexis Ohanian / Breadpig