Don't let the hoodie and sneakers fool you. Mark Zuckerberg is no wet-behind-the-ears CEO.
Facebook's chief executive turns 28 tomorrow, setting in motion the social network's biggest week ever.
The company is expected to start selling stock to the public for the first time and begin trading on the Nasdaq Stock Market on Friday. The IPO could value Facebook at nearly $100 billion, making it worth more than such iconic companies as Disney, Ford and Kraft Foods.
At 28, Zuckerberg is exactly half the age of the average S&P 500 CEO, according to executive search firm Spencer Stuart. With eight years on the job, he's logged more time as leader than the average CEO, whose tenure is a little more than seven years, according to Spencer Stuart.
But Zuckerberg will be about the same age as Michael Dell and older than Steve Jobs when those two took their companies, Dell Inc. and Apple Inc., public.