Costolo’s new position takes effect immediately. He joined the microblogging company as chief operating officer just one year ago from his position as group product manager at Google. Prior to that he worked as CEO at online RSS ad network FeedBurner and before that manager at Accenture.
Williams announced Costolo's promotion on the Twitter Blog, "During his year at Twitter, he [Costolo] has been a critical leader in devising and executing our revenue efforts, while simultaneously and effectively making the trains run on time in the office."
On his changing role, Williams said, “I’ll be completely focused on product strategy.”
According to the blog, Twitter records 90 million tweets daily and has grown from 3 to more than 165 million registered users over the past two year.
“Growing big is not success, in itself. Success to us means meeting our potential as a profitable company that can retain its culture and user focus while having a positive impact on the world,” added Williams.