He is an investor, director and advisor to a variety of businesses, most in the software and Internet domain, including Jingle Networks, Odeo, Eventful, Krugle, Ambient Devices, del.icio.us, IronPort, RockYou!, myYearbook, Knewton, VideoEgg, Wikia and Discourse.
He got his first taste of the startup world when was a member of the Mayfield Fellows Program at Stanford University which led to his internship at Odeo, the company that eventually gave rise to Twitter.