LOS ANGELES  When Conan O’Brien wanted to start a Web site last winter, he was reminded that he did not own his dot-com name, ConanOBrien.com.

Gainfully employed by NBC for some two decades, a personal Web site had hardly been a priority until, well, his tenure as host of “The Tonight Show” screeched to an end in January. Suddenly he needed a new platform. He joined Twitter, and last month, helped by just a few tweets, Mr. O’Brien largely sold out his 30-city comedy tour, which starts on Monday in Eugene, Ore.

Mr. O’Brien was a Web Luddite, but now he is making up for lost time. He resembles many other entertainers who have turned their corners of the Web into self-referential, self-promotional sales tools, but he stands out for his humor and his speed of adoption. Case in point: he has been picking a Twitter fight with Justin Bieber, the 16-year-old singer who has 1.75 million followers on that site, almost one million more than Mr. O’Brien.

Because ConanOBrien.com is owned by an online squatter, Mr. O’Brien’s representatives decided to adopt Team Coco, one of his fans’ chosen names, as the host’s own. They even licensed a fan’s artwork for the tour poster. TeamCoco.com is a single Web page now, but as the tour gets under way, the site is to expand.