





At CES, Twitter CEO Dick Costolo revealed that 40% of all tweets come from mobile devices, demonstrating mobile's increasing importance to the social media company.

On stage at the AllThingsD event at CES, Costolo bantered with Kara Swisher about why Twitter is at CES, its plans to become simpler and more consistent across platforms, and the impact of its celebrity users.

During the course of the conversation, Swisher asked Costolo which devices and operating systems are the most important to Twitter's future and its health. Costolo responded by saying that 40% of all tweets are now composed on mobile devices, up from around 20% to 25% a year ago.

Twitter mobile usage exploded with the release of the company's official iPhone, iPad, Android and BlackBerry apps. The mobile website, SMS, Twitter for iPhone and Twitter for BlackBerry are the most popular Twitter apps after the company's website.

Costolo also revealed that Twitter now has 350 employees, 100 of whom were hired just recently in Q4 2010.