The camera phone is perfect for the social networking era. But even smartphones have a limitation: you need to hold them.

As the smartphone has pushed some camera companies off a cliff, a tiny, ultrahigh-resolution camera that can record that very feat has taken off into the stratosphere, figuratively and literally.

The GoPro, which costs $200 to $400, was mounted on Felix Baumgartner as he sky-dived 39 kilometers. It has been affixed to jets traveling at Mach 5 and surfboards sent down 30-meter waves.

GoPro has sold three million cameras in three years. The market research firm IDC says that makes the GoPro the most popular video camera in the country.

In October, the company, which began 10 years ago with a disposable camera strapped to surfers' wrists, unveiled the Hero3. You might think a product announcement from a camera company would feel like the lead-up to a funeral. But it felt more like a celebration for someone who was going to live forever. Big-wave surfers showed their GoPro shots to sky divers, who, in turn, had their own stories to show.

How did this happen? Nick Woodman, the founder and inventor of GoPro, says, "Right place, right time."

It was almost that simple. Mr. Woodman, 37, made the first, crude GoPro when he went to Indonesia on a surfing trip. He wanted to take pictures of a friend in the water. But when he turned the camera around to take pictures of himself, he realized the company's potential.

"The big 'aha' moment was in 2007, when we realized the bigger opportunity wasn't just making wearable cameras for photographers," Mr. Woodman said. "It was making wearable cameras for people to photograph themselves."

This was happening just as Google was buying YouTube, and sites like Twitter and Facebook were going mainstream.

Mr. Woodman began selling inexpensive mounts that could attach the GoPro to anything: surfboards, bicycles, helmets, body harnesses, cats, you name it.

What happened next was astounding: people started to develop a relationship with GoPro.

"One of the magical things that started happening with the company was our customers felt compelled to give us credit in their photos and videos," Mr. Woodman said.

A search on YouTube for "GoPro" nets more than half a million videos. Millions of photos and videos litter social networking sites, all tagged with the camera's name in the same way people highlight their friends.

Now, the appeal is moving beyond extreme sports enthusiasts, whose idea of fear is sitting in a cubicle, to the people who sit in cubicles watching GoPro videos. The big camera companies are trying to displace GoPro, but they may be a decade too late.

"For the last 50 years, companies like Nikon and Canon have been focused on precision, which has its benefits but also has its limits," said Chase Jarvis, a photographer and director. "GoPro is incredibly disruptive to these legacy camera makers, and I can tell you, their launch parties feel a little bit different. They are from a different culture."

Brian X. Chen contributed reporting.

The New York Times