Twitter co-founder steps down as CEO

Williams, in a post on the company blog, said Twitter's chief operating officer, Dick Costolo, would take over as CEO of the San Francisco-based startup.

"I am most satisfied while pushing product direction," Williams said. "Building things is my passion, and I've never been more excited or optimistic about what we have to build.

"This is why I have decided to ask our COO, Dick Costolo, to become Twitter's CEO," he said. "Starting today, I'll be completely focused on product strategy."

Williams said Costolo, who joined Twitter a year ago, "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.

"Given Dick's track record as a three-time successful CEO, I'm confident we can make this a smooth transition.

Twitter, which allows users to fire off messages of 140 characters or less known as "tweets," has enjoyed skyrocketing popularity since it was launched in 2006 by Williams, Jack Dorsey and Biz Stone.

Williams said Twitter now employs around 300 people, up from 20 when he took over as CEO from Dorsey two years ago.

"By all accounts Twitter is on a roll," he said. "We've redesigned our website to great user feedback.

"Our user and usage numbers are growing at a rapid clip all around the world. We've launched an early, but successful, monetization effort.

"In those same two years, we grew from three million registered users to more than 160 million today," Williams said.

The Twitter co-founder added that "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," he said.

Source: AFP