StumbleUpon co-founder and CEO Garrett Camp has stepped down from the company. He will remain as Chairman of the board though. StumbleUpon is now looking for a new CEO. Camp has been CEO of StumbleUpon for 10 years since he created it as a grad student. He was CEO when eBay bought the company for $75 million and when he bought it back with several investors. StumbleUpon has 25 million registered users. ?It was my first job and my first love,? said Camp. Camp also founded an on-demand ride service called Uber and he is chairman there as well.