Jack Dorsey, the Twitter co-founder responsible for the messaging service's first tweet five years ago, is returning to oversee the company's products.
Twitter is tapping into its creator's ingenuity as it tries to build upon its popularity to make more money by selling more ads. The privately held company doesn't disclose its finances, but research firm eMarketer Inc. estimates Twitter will bring in advertising revenue of about $150-million this year.
Mr. Dorsey, Twitter's original CEO, announced his new role Monday on his Twitter account. He says he intends to remain CEO of a mobile payments service called Square that's located near Twitter's San Francisco headquarters.
As part of his new job, Dorsey's title has been changed from Twitter's chairman to executive chairman.
"I'm thrilled to get back to work at Twitter," Mr. Dorsey tweeted Monday.
Mr. Dorsey stepped down as Twitter's CEO during the fall of 2008 and was replaced by another co-founder, Evan Williams. After that change, Twitter's online audience ballooned from about 3 million users to about 200 million now. Mr. Williams handed over the reins to Twitter's current CEO, Dick Costolo, nearly six months ago.
Mr. Costolo welcomed Dorsey back in a post on his Twitter account.
Even before Monday's announcement, Mr. Dorsey had been making increasingly frequent visits to Twitter to hang out and swap ideas with the company's employees, co-founder Biz Stone told The Associated Press in a recent interview.
Mr. Dorsey began tinkering with the concept for Twitter as a side project within another company that Williams was running. Even after he stopped working for Twitter, Mr. Dorsey remained vested in its success because he is among the company's largest shareholders.