After a decade building and running the online discovery engine StumbleUpon, CEO Garrett Camp announced this week he's stepping down from his position, and assuming the role of company chairman.

In a blog post, Camp said he's undergoing the transition to be: "focused on the vision and strategy of the company while also starting a new venture." Camp is also founder and chairman of private car-for-hire start-up Uber. The other new venture he refers to in the post is still a mystery.

Camp and co-founder Geoff Smith began creating StumbleUpon as a side project while Camp was a graduate student in Calgary, Canada. He didn't come to Silicon Valley until 2005, for a meeting with Brad O'Neill, and early StumbleUpon user-turned-investor. 

In 2007, Camp and Smith sold StumbleUpon to eBay, where it stagnated.

"About a year in, after the acquisition, we started realizing it wasn't as exciting," Camp told Inc.'s Christine Lagorio at South by Southwest Interactive in March. "When you're a start-up, everyone has stock options, everyone is energized. If you don't take a risk, the status quo will continue. "

He and investors bought back StumbleUpon in 2009, and the company has shown remarkable growth since then. The site has grown from 5 million to 25 million users today.  

"This is the most exciting phase the company has seen—and it's three years almost now," he said. "The majority of our growth has come recently, and when something goes viral on StumbleUpon, it's crazier than Facebook."

Inc. reported in 2011 on how Camp sold, and, remarkably, re-acquired his own company. Here's the full story, in his own words, as told to April Joyner.

For years, Garrett Camp ran StumbleUpon, a service for discovering and sharing webpages, part time while finishing his master's thesis at the University of Calgary. In 2007, within a year of moving the company to San Francisco, he sold it to eBay. In 2009, he organized an investor group to buy the company back.

At eBay, I had a boss, but I still managed all the product engineering. The day-to-day flow really wasn't that different. But we weren't getting the same people to apply to join. We were seeing people who were looking for a conservative, stable job rather than something with a little more risk and a lot of upside.

The lack of flexibility was the biggest issue. At one point, we had to hire a database administrator, and they said, "Oh, there's a hiring freeze." And I was like, "Sure, eBay has a hiring freeze, but how can you stop us from hiring the one critical position we need to keep the site running?"

I started thinking about a spinout in the summer of 2008. I talked to my boss, and he talked to other executives at eBay. I also contacted one of my old investors, Ram Shriram, who talked to people he knew on eBay's board. Because we were part of a public company, we had to be discreet.

The spinout was a complicated negotiation. It took six months of discussions, and then several months to find investors. I'd never really made the rounds of Sand Hill Road before. I'd had a lot of casual meetings with investors, but with the spinout, I actually had to give presentations and say why StumbleUpon was a good investment.

Once we became independent again, in April 2009, there was just a sense of energy and excitement. The spinout basically reset us to a start-up. We had years of experience and a lot of scale, yet we were a brand-new company. All of a sudden, we were able to attract great candidates. Within nine months, we were on full throttle. When we left eBay, we had 300 million stumbles [page recommendations] per month. Now we have over 1 billion. We've released new mobile applications and relaunched our ad system. Our agility and nimbleness are a lot higher, because we have a lot more people who really want to make something cool and have a big impact.

Published on: May 9, 2012