"I did not spend one penny on advertising," Conan O'Brien said in a Q&A at Google's headquarters discussing the social media push that fueled his sold-out comedy tour and planned return to TV. "I sent out one tweet that directed people to a web site where you could buy your ticket. That was it. And the show sold out in a couple of hours across the country. And that's got everybody, a lot of people rethinking how things are marketed."

O'Brien, in a 48-minute session with Google employees posted on Youtube, said he didn't have to do radio interviews or "hawk my show" at all.

"I think people are starting to understand that the world has completely changed," he said.

O'Brien talked about NBC's reactions to the Internet wave of support for him, noting the network thought O'Brien was orchestrating the campaign and wanted him to stop it.

"They just didn't understand what was happening," he said. "I think they still don't understand what's happening."

O'Brien said he "had nowhere else to go" when he started using Twitter because he was legally prohibited from appearing on TV, radio or performing on the Internet.

"So I was literally like a prisoner in a 14th-century cell writing little things on a scrap of paper and throwing them out the window and hoping a peasant would go by and, 'Hey, what's this?'"

O'Brien said his studio bosses considered muffling his tweets but realized the "absurdity" of shutting down his Twitter account.

O'Brien talks about TV's "dismissive" attitude toward the 'Net noting "they tend to deride what they don't understand" in the session, as well.