Jack Dorsey: “My entire focus is to make sure that Twitter is going to be amazingly successful.”  Photograph: Justin Tallis/AFP/Getty Images

For the past two years, the normally dapper Jack Dorsey has hardly been seen at the offices of Twitter, the social networking company he co-founded, e(...)

Outgoing Twitter chief executive Dick Costolo’s impending departure has been influenced by investors unhappy with stagnant user growth and the absence of profit. Photograph: Richard Perry/The New York Times

Some shock waves went through Silicon Valley this week when Twitter chief executive Dick Costolo abruptly announced he was stepping down. The microbl(...)

  Dick Costolo, Twitter’s embattled chief executive, at the New York Stock Exchange during the company’s market debut. Photograph: Richard Perry/The New York Times

Twitter chief executive Dick Costolo abruptly announced he was stepping down on Thursday amid increasing scrutiny of the company’s slow user growth an(...)

Twitter and police are investigating alleged threats made by Islamic State militants against the social media network’s co-founder Jack Dorsey (pictured) and other employees. Photograph: Scott Eells/Bloomberg.

Twitter and police are investigating alleged threats made by Islamic State militants against the social media network’s co-founder and other employee(...)

Facebook has a new empathy team, whose job is to go around feeling the pain and pleasure of others and translate the experience for the benefit of its engineers. Photograph: Martin Keene/PA Wire

Most Silicon Valley companies are run by geeks. One of the drawbacks of being a geek is that dealing with other human beings tends not to be a strong (...)

Pictured at Web Summit 2014 (l to r) Jeff Hagins of SmartThings, Paddy Cosgrave of Web Summit and Anna Scally, partner and Head of Technology, Media and Telecoms at KPMG.

The sheer scale of the numbers associated with the 2014 Web Summit can almost distract from what happened at the event: billion-dollar businesses, mil(...)

Paddy Cosgrave: will host his F.ounders dinner, an invitation-only nosh-up of elites

Speaking of the Web Summit, the organisers have made a last-minute hire to run their press operation, PSG Communications, which was born out of the me(...)

Vivienne Harr (centre)  ringing the bell at the New York Stock Exchange when Twitter went public with  actor Patrick Stewart (right). Photograph: Andrew Burton/Getty Images

At Silicon Valley’s Techmanity conference, the crowds hadn’t only come to see actor Jared Leto lecture about entrepreneurship and a Weezer concert tha(...)

Twitter has not yet decided how to charge advertisers for its commercial service but it is experimenting with a tiered pricing system like that for its promoted tweets or affiliate partnerships.

Twitter is entering e-commerce by encouraging users to make purchases on the messaging platform in a new tactic to win over advertisers.The home of th(...)

Paddy Cosgrave: changed name of Dublin event back to Web Summit because, according to his spokeswoman, The Summit is hard to find on Google.

The two protaganists in the row between Web Summit and Summit Series have trod strikingly similar paths.Elliott Bisnow first showed an entrepreneurial(...)