Hooman Radfar (born July 14, 1980, London, England) is an American technology entrepreneur. He is a partner at Expa, a San Francisco based start-up studio. Previously he was co-founder and CEO of AddThis. AddThis provides the most widely used social media tools and analytics platform for web site creators. According to web measurement firm ComScore, in 2013 the platform reached over 97% of users in the United States and 1.6 billion users world-wide.