One of the top tech companies in San Francisco floating just below the surface of broader consumer consciousness is StumbleUpon, the discovery engine that co-founder and CEO Garrett Camp calls the "forward button for the internet."
StumbleUpon helps you find and share great content out along The Long Tail, and the more you use it the better it becomes at finding those gems that make the web, at its best, so entertaining and informative.
It's a bit unusual among startups in that it's about ten years old, and has already been through a major acquisition (for $75 million by eBay in May 2007) followed by an even more unusual event in April 2009, when its founders, including Camp and his co-founder Geoff Smith, bought it back from eBay at a deep (though undisclosed) discount.
Once upon a New Year's Eve, after StumbleUpon founder and CEO Garrett Camp dropped $800 on three cab rides, he decided there had to be a better way to get a ride when you really needed one.
He started Uber, a marketplace that connects you via an iPhone or android app with your own private driver. That may sound simple enough but take a peek under the hood, and it turns out be one gigantic math problem, says Ryan Graves, Uber's VP of Operations.
"A lot goes into matching drivers with riders," he told me, "and we measure everything. After someone opens the app, how often do they refresh the screen? How fast does the driver respond? How accurate is his ETA?"
Using GPS, Uber's system identifies the closest on-duty driver to where the rider's location. The driver has 15 seconds to respond. "Drivers love it," says Graves, "because it means less time with an empty backseat. When they're empty they are treating the Uber app like it's hot."