THR's 2012 Digital Power 50

Celebrities and Twitter already go hand in hand, but under Costolo, 48, the social media monster continues to build its global reach to create a powerful analytics tool and marketing machine -- and create revenue for its popular service with Promoted Tweets, Trends and Accounts, targeted to reach the most relevant followers. Paramount launched its first marketing campaign using Twitter's new tools for Super 8, aiding its $259.7 million worldwide box-office take. Research firm eMarketer has estimated Twitter's worldwide ad revenue will hit $260 million in 2012, up from $45 million in 2010.

PHOTOS: THR's 2012 Digital Power 50