Today in Tech: Google snaps up Zagat

• Dick Costolo: Twitter has 100 million active users

  The rapidly growing social network held a so-called State of the Union to reveal new stats about its ongoing rise.

  FORTUNE -- This week, Twitter CEO Dick Costolo hosted a small gathering at Twitter headquarters in San Francisco to give a brief update on the social network's growth. His self-described "State of the Union" highlighted a number of new user stats. The overall message? That Twitter thinks it is in a MORE

  JP Mangalindan, Writer - Sep 8, 2011 2:56 PM ET
  Posted in: Brazil, Dick Costolo, DoubleClick, Fortune (magazine), Google, Google Analytics, Jack Dorsey, Twitter

• Dick Costolo on how Twitter makes -- and might make -- money

  With a multi-billion-dollar valuation and relatively small revenues, Twitter is Exhibit A for those who believe Silicon Valley is experiencing another bubble. At Fortune's Brainstorm Tech conference on July 19, the company's CEO, Dick Costolo, explained how the company's business works, including what ad products its customers are buying and how Twitters sells to them. He even hinted a major future product area: capitalizing on the commerce currently being conducted MORE

  Adam Lashinsky, Sr. Editor at Large - Jul 26, 2011 8:34 AM ET
  Posted in: Advertising, Dick Costolo, Google, Twitter

• Brainstorm video: Dick Costolo on Twitter's business model

  Twitter CEO Dick Costolo sat down with Fortune's Adam Lashinsky at Brainstorm Tech in Aspen, CO to discuss the company's future.

  Below is an unedited transcript of the talk.

  ADAM LASHINSKY:  Dick, thanks for being here.

  DICK COSTOLO:  Sure.

  ADAM LASHINSKY:  Welcome back to Aspen.  You were here last year.  Biz Stone was with us the year before that.

  I feel like we have a small elephant in the room, and we should get it MORE

  Fortune Editors - Jul 19, 2011 7:34 PM ET
  Posted in: biz stone, Dick Costolo, Jack Dorsey, Twitter

• Today in Tech: Brainstorm Tech starts, Borders closes

  Fortune's curated selection of the day's most newsworthy tech stories from all over the Web. Sign up to get the newsletter delivered to you every day.

  * Fortune's annual Brainstorm Tech conference kicks off later this afternoon with the day's speakers including Twitter CEO Dick Costolo, Dreamworks Animation CEO Jeffrey Katzenberg, Square COO Keith Rabois, and Stephanie Tilenius, Google VP of Commerce and Payments. Keep checking the Web site throughout the day for the MORE

  JP Mangalindan, Writer - Jul 19, 2011 3:30 AM ET
  Posted in: All Things Digital, Borders Group, Dick Costolo, Google, Jeffrey Katzenberg, Keith Rabois, Marissa Mayer, Stephanie Tilenius

• Biz Stone departs, Trouble@Twitter continues

  Another one of Twitter's founders, Biz Stone, will leave the start-up.

  FORTUNE -- In the continuing game of musical chairs among executives at Twitter, another of the company's founders is leaving. In a June 28 blog post, Biz Stone announced he will join founder Evan Williams, who left the CEO position last fall, and Twitter's former vice president of product Jason Goldman, who left the company abruptly in December. The trio MORE

  Jessi Hempel, writer - Jun 28, 2011 4:50 PM ET
  Posted in: biz stone, Dick Costolo, Evan Williams, Jack Dorsey, Jason Goldman, Twitter

• Jack Dorsey: The man with two brains

  The cofounder of Square is also logging a full workload at Twitter, down the street. His plans for both startups remain grand (think IPO, not buyout).

  FORTUNE -- Twitter is not for sale. Jack Dorsey, the cofounder-turned-prodigal son made this clear in an interview Wednesday with All Things D columnist Kara Swisher at the D9 tech conference in Rancho Palos Verdes, Calif.

  Instead, it's more likely an IPO is in the compay's MORE

  Jessi Hempel, writer - Jun 1, 2011 9:23 PM ET
  Posted in: Apple, Dick Costolo, Jack Dorsey, Kara Swisher, Square, Twitter

• Trouble @Twitter

  Boardroom power plays, disgruntled founders, and CEO switcheroos are clipping the wings of this tech high flier.

  By Jessi Hempel, senior writer

  FORTUNE -- In March, shortly after Jack Dorsey went back to work for Twitter, the company he co-founded four years ago, he did a Q&A session with an entre­preneurship class at Columbia Business School. As students tapped away on their laptops (were they sending tweets?), Dorsey, 34, answered questions about MORE

  Apr 14, 2011 5:00 AM ET
  Posted in: biz stone, Dick Costolo, Evan Williams, Jack Dorsey, micro-blogging, social media, Twitter

• Jack's back: Dorsey speaks on his plans for Twitter

  Despite getting pushed out of the company he founded, Dorsey says he doesn't regret a thing and paints the broad strokes of Twitter's path forward.

  FORTUNE -- The news buzzing all around Silicon Valley is probably one and the same: "@jack is back."

  @jack is, of course, Twitter creator and co-founder Jack Dorsey, who confirmed, via Twitter, naturally, that he's returning to MORE

  JP Mangalindan, Writer - Mar 29, 2011 3:17 PM ET
  Posted in: Chairman, Columbia University, Dick Costolo, Evan Williams, iPhone, Jack Dorsey, Silicon Valley, Twitter

• Today in Tech: iPhone 5 cheaper, voice features, too

  A curated selection of the day's most newsworthy tech stories from all over the Web. Sign up to get the newsletter in your inbox every morning.

  President Obama wined and dined many of Silicon Valley's top execs last night during his first official trip to the San Francisco Bay Area. On the guest list: Apple CEO Steve Jobs, Facebook CEO Mark Zuckerberg, Twitter CEO Dick Costolo, Google CEO Eric Schmidt, Oracle CEO MORE

  JP Mangalindan, Writer - Feb 18, 2011 8:33 AM ET
  Posted in: Apple, Barack Obama, Carol Bartz, Cisco, Dick Costolo, Eric Schmidt, Facebook, Google, Grand Central Terminal, HauteLook, iPhone, iPhone 5, Larry Ellison, Mark Zuckerberg, New iPhone, Oracle, President Obama, Steve Jobs, Twitter, Yahoo