Twitter needs to stop comparing itself with Facebook

As chief Dick Costolo departs, investors must stop pushing Twitter to be the next big social media network and focus on its simple strengths

When the chief executive of Twitter announced he was stepping down on Thursday, staff knew there was only one way to mark his surprise departure. A hashtag on the social network was created - #thankyoudickc - for colleagues to lavish praise on Dick Costolo, a former standup comedian turned Silicon Valley entrepreneur. "140 characters certainly not enough #thankyoudickc," said one employee.

In his nearly five years in the job, Twitter has grown from a few million users to 302 million. Why then would the 51-year-old leave one of the most high-profile jobs at one of the tech industry's brightest shining stars? Despite his popularity and success in helping the company mature, Costolo has always been caught between conflicting visions of what Twitter is capable of being: a social utility that promises to be a democratic civic space for all, or a commercial service.