The world's most followed Tweeter on Twitter

For Ashton Kutcher, winning the race to 1 million followers on Twitter before CNN was not about being victorious in a popularity contest.

Instead, it illustrated that "one individual could have as much influence on a social network as a media conglomerate," he said at Fortune's Brainstorm: Tech conference.

He also noted that it signifies a shift in turning media back over to consumers, who are now also content creators and editors. This dynamic "has and will forever change media," Kutcher said.

Now more than three months after hitting the 1 million mark, followers of his Twitter handle "aplusk" come in at 2.9 million. He said he Tweets to stay close to his fans, to raise awareness about causes that interest him, and simply because it's fun.

It also allows him to engage his fans even more directly by involving them in the creative process. During the making of "Five Killers" (due out next year), Kutcher was looking for a joke to tell during a scene. After Tweeting about it, hundreds came pouring in and one got plugged into the movie. "We'll see if it makes the cut," he said.

It's a smart marketing tool as well. Kutcher said that movie studios spend half their budget for a film just trying to let a potential audience know it's being released. "I can do it for free by pushing a button," he said.

Responding to the notion that movie stars are becoming less important, Kutcher said, "I don't have three million followers because I'm really good at putting up content." He noted that he shuts down a website every day because he sends too much traffic to it from his Twitter feed.

But he did acknowledge that people in the entertainment business are going to have to start to embrace the web and leverage the platform or they won't be able to demand the same fees.

Kutcher said that he's starting to see the convergence of television and digital media, and his company, Katalyst Media, is trying to capitalize off of that by working across multiple platforms and finding the intersection between them.

"If we can have our foot in that arena and understand that space…we'll have a leg up when convergence actually does take place," he said.

While Kutcher is currently a Twitter devotee, he said that it's likely that someone else might create a  microblogging tool that has a better search and syndication function. But right now he's happy to Tweet anywhere from zero to 20 times a day to lift the "curtain" between him and his fans.

He's also not above poking some fun at himself. In the run up to the conference, Kutcher Tweeted: "Headed to the Fortune tech Brainstorm in Pasadena. Gonna do an onstage interview. Quick someone invent me [an intelligence] pill."

But when it comes to Twitter, the world's most popular Tweeter knows what he's talking about.