But Gladwell.com is not a promotional device, Gladwell said. The site has excerpts from "The Tipping Point," but his book is not available through the site. Gladwell said he started Gladwell.com more out of a sense of literary civitas than marketing opportunism.

"I have run into some people who think it is arrogant to have your own Web site," he said. "But it's a pain to fax people your articles all the time, which is the main reason I have the Web site. My view is that it is not any different from publishing a collection of your articles in book form. Certainly charging for stuff that's already been published seems slightly more arrogant than making it available on the Web site for free."

The greatest advantage of Gladwell.com, Gladwell said, is response from visitors to the site, who e-mail their comments and ideas to Gladwell, and also unwittingly offer themselves up as a kind of human petri dish for Gladwell's study.

"You'd be surprised at what you learn," Gladwell said. "It's not this selfless exercise. An incredible number of my ideas come from incredibly random conversations I have. In fact, all of them do. So the more random conversations the better, and these are all small, random conversations."