Meet Twitter's top funny man, Dick Costolo: September 10, 1963: Dick Costolo is born in Royal Oak, Mich., a Detroit suburb. As a teen, he learned to code computer games. While studying computer science at the University of Michigan, Costolo took a theater studies class to fulfill an arts requirement. Bitten by the performance bug, he became a regular at campus open-mike nights. After earning his degree in computer science, Costolo turned down several tech jobs to join Chicago's Annoyance Theater improv troupe. (Fellow cast members included future comedy star Steve Carrell.) Costolo eventually gave up comedy and worked eight years at Andersen Consulting, where he helped develop the first Web-based enterprise training application. He later cofounded and sold two Web companies before launching Feedburner, which helped bloggers syndicate content. In June 2007, Google (GOOG) bought Feedburner for a reported $100 million. The next month, Costolo was among a group of high-profile "angel" investors who put money into Twitter's first funding round. After Costolo left Google in July 2009, Twitter Chief Executive Evan Williams invited him to fill in as CEO while Williams took paternity leave. Costolo ended up joining as chief operating officer that fall; a year later, Williams stepped down and Costolo ascended to the top job. Quotable: "We just raised more money than I've ever seen before. And we did that because we want to be able to grow the company and not be beholden to the public markets until we decide we want to be." -- Costolo in September 2011, after the company closed a then-record $400 million venture capital round.
Source: University of Michigan; Mercury News research