- Age: 51
- Known for: Twitter
- Quote: "You may think people are fooled when you tell them what they want to hear. They are not fooled."
It's quite a change to go from being a comedian to becoming the CEO of one of the busiest destinations on the internet, but Dick Costolo has managed the transition well.
Soon after graduating from college, Costolo joined the same comedy improv troop that Mike Myers and Tina Fey started out in, and he even worked with Steve Carell.
But the tech world came calling and Costolo left the laughter behind and went into web design and consultancy. In 2007 he founded FeedBurner, a web feed management tool that was eventually bought by Google. He stayed with Google for two years, then followed the bird song to Twitter.
Twitter may have been around for three years when Dick Costolo joined in 2009, but under his tutelage the site has seen explosive growth.
Costolo originally joined the micro-blogging site as chief operating officer, but within a year he was moved up to CEO. Since then the site's user base has quadrupled in size to around 284 million active users and Twitter as a company has grown threefold.
Costolo took over from Twitter's original co-founder, Ev Williams, who went on to create blogging platform Medium.
Since becoming CEO, Costolo has put a number of measures in place to try and make money out of Twitter. These include adding promoted tweets, opening up Twitter's direct message functionality and adding video sharing to the site. He's also overseen the creation of two spin-off services: Vine and Periscope.
At its heart, Twitter is the same simple service that Ev Williams and Jack Dorsey created back in 2006, but with Costolo at the helm it's now a viable business too.
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