Twitter promotes Costolo to CEO after Williams resigns

Twitter promoted COO Dick Costolo to lead the company after co-founder and CEO Evan Williams resigned to focus on the microblogging phenom's product strategy efforts. Williams announced the move in a Twitter Blog entry Monday: "I am most satisfied while pushing product direction. Building things is my passion, and I've never been more excited or optimistic about what we have to build," he writes. "This is why I have decided to ask our COO, Dick Costolo, to become Twitter's CEO. Starting today, I'll be completely focused on product strategy."

Williams took over the CEO reins in late 2008, replacing fellow co-founder Jack Dorsey; during his tenure, the firm transformed from cult phenomenon to mainstream juggernaut, revolutionizing how users interface with the world. Tweets--the 140-character messages that make up the global Twitter dialogue--are now the preferred medium of communication for more than 165 million registered users, among them executives, celebrities, athletes and everyday people. Costolo joined Twitter in 2009 after founding Feedburner, a startup providing media distribution and audience engagement services for blogs and RSS feeds. Google acquired Feedburner in 2007.

Twitter's CEO transition arrives as the company continues its efforts to build an advertising business that monetizes its rapid growth. Last week it introduced Promoted Accounts, a new advertising solution enabling marketers to boost their audience by paying Twitter to automatically suggest that users follow brands with similar interests. Promoted Accounts joins existing Twitter initiatives including Promoted Tweets (which appear at the top of updates) and Promoted Trends (appearing on lists of trending topics). With the introduction of Promoted Accounts, Twitter shuttered Earlybird Exclusive Offers, which promised time-sensitive deals to users who follow the @earlybird tweet stream. Twitter launched the Earlybird program in early July 2010, touting offers created expressly for its user community--advertiser partners determined the terms of each promotion, including availability, amount and price, with Twitter earning a cut of resulting revenues.

For more on Twitter's leadership change:
- read this blog entry

Related articles:
Twitter launches Promoted Accounts, shuts down Earlybird
Twitter bans third-party advertising alternatives
Twitter unveils Promoted Tweets ad effort
Twitter for iPhone hits the App Store
Twitter's Tweetie acquisition fuels developer anxiety