O'Brien is the head of business development for Tapulous, an iPhone application which was the top game downloaded in 2008 and which has more then 6 million unique users. The game's popularity has helped Tapulous sell custom, musician-branded apps, including a Weezer Christmas app last year. "Tap Tap Revenge 2,"just released on March 1, 2009, became the most downloaded free app on Apple's iPhone app store after it's first three days, with over 500,000 downloads. Prior to joining Tapulous O'Brien headed Music Businsess Development for StuHub. He resides in San Francisco, CA and attended University Of California-Berkeley '96, and Walter Haas School of Business.