25 of 51
BACKNEXT
24. Dick Costolo
24. Dick Costolo
CEO, Twitter

In October, Twitter co-founder Evan Williams handed Costolo -- a onetime improv performer -- the top spot, a tacit acknowledgment that finding a way to make Twitter profitable has become the top priority. The microblogging service has grown to 160 million registered users -- 65% of the Fortune 100 had active accounts by this summer -- though monetizing that base has been tough. This year the company hired Adam Bain from News Corp. and Ali Rowghani from Pixar to divine new revenue streams. Perhaps the company's new ad platform, Promoted Trends, will help.

--P.N.



NEXT: 25. Ratan Tata
Last updated November 19 2010: 10:47 AM ET
After a month of rabid online voting you crowned your own Businessperson of the Year. More
Executives from Silicon Valley to Hollywood to Wall Street admires his savvy persistence - and his company's cool culture. The secret to the Netflix CEO's success? He never stops looking over his shoulder. More
Michael Dell was 21 when he first appeared in Fortune. Bill Gates made the cover when he was 30. Here's a look back at some of today's biggest business leaders when they were climbing the corporate ladder. More
Market indexes are shown in real time, except for the DJIA, which is delayed by two minutes. All times are ET. Disclaimer LIBOR Warning: Neither BBA Enterprises Limited, nor the BBA LIBOR Contributor Banks, nor Reuters, can be held liable for any irregularity or inaccuracy of BBA LIBOR. Disclaimer. Morningstar: © 2013 Morningstar, Inc. All Rights Reserved. Disclaimer The Dow Jones IndexesSM are proprietary to and distributed by Dow Jones & Company, Inc. and have been licensed for use. All content of the Dow Jones IndexesSM © 2013 is proprietary to Dow Jones & Company, Inc. Chicago Mercantile Association. The market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved. FactSet Research Systems Inc. 2013. All rights reserved. Most stock quote data provided by BATS.