Practical mother, visionary son

David Karp sold his Tumblr blogging service to Yahoo last week for $1.1 billion. The school dropout had realised as far back as 2000 that video would one day rule gadgets.

When David Karp was 14, he was clearly a bright teenager. Quiet, somewhat reclusive, bored with his classes at the Bronx High School of Science. He spent most of his free time in his bedroom, glued to his computer.

But instead of trying to pry him away from his machine or coaxing him outside to get some fresh air, his mother, Barbara Ackerman, had another solution: she suggested that he drop out of high school to be home-schooled.

"I saw him at school all day and absorbed all night into his computer," says Ackerman. "It became very clear that David needed the space to live his passion. Which was computers. All things computers."

Now 26 years old, Karp never finished high school or enrolled in college. Instead, he played a significant role in several technology start-ups before founding Tumblr, the popular blogging service that agreed to be sold to Yahoo for $1.1 billion last week. With an expected $250 million from the deal, Karp joins a tiny circle of 20-something entrepreneurs, hoodie-wearing characters like Facebook's Mark Zuckerberg and Foursquare's Dennis Crowley, who have struck it rich before turning 30.

"When I first met David he was 20 years old and wearing sneakers and jeans," says Bijan Sabet, a general partner at Spark Capital, who was one of the first people to invest in Tumblr. "But I knew he was one of these rare entrepreneurs that grew up on the Web and who could come up with an idea, build it himself, and then ship it that night."

Tall and willowy, with a mop of brown hair and piercing blue eyes, Karp typically dresses in jeans, t-shirt and sneakers. He speaks at a rapid clip and, often, for minutes without stopping. Technically, he never graduated, which he cracked in an interview is "hopefully not a condition of Yahoo employment."

After dropping out and working for a time in small New York tech outfits, Karp made his way to Tokyo, where he worked for several months for a start-up. He returned to the United States and became the chief technology officer for UrbanBaby, an Internet message board for parents. CNET Networks bought UrbanBaby in 2006, and Karp took the several hundred thousand dollars he made from the sale to start his own company, called Davidville. One of Davidville's projects was a simple blogging service called Tumblr. "Where I feel the most productive and engaged is when I'm buried in code, buried in some project, tweaking some designs," Karp says. "I'm certainly introverted."

Fred Seibert, a television producer who was MTV's first creative director, first met Karp in 2000 while he was still in high school. Seibert says it wasn't long before Karp became invaluable. He asked him to build the site for his new company, a Web video production outfit called Next New Networks. "He comes in two weeks later and he hasn't done it," Seibert recalls. "I thought he was being a flaky 19-year-old. But he said, 'No, no, your idea is just so 2000.' "

Karp pulled out a Sony PlayStation Portable gaming device and told him that soon, Apple would be releasing an iPod with video capabilities. "He said, 'This is the way people are going to watch video and you really ought to be there.' " Next New Networks was one of the first video products on iTunes and was acquired by Google for around $50 million. "Because of his prescience and timing, we were ahead of the curve," Seibert says. Seibert became an investor in Tumblr and sits on the company's board.

Karp, who lives in a $1.6 million one-bedroom loft in Williamsburg, Brooklyn, with his girlfriend and dog, says he is staying put in New York and with Yahoo. He intends to "figure out something" with philanthropy. And one day he might even go to college. "At least I should be able to afford it," he says.

©2013 The New York Times