http://gma.yahoo.com/causes-founders-400m-facebook-mistake-082306041--abc-news.html

Joe Green was Mark Zuckerberg's roommate in college. And now, he is knowm to have made the $400 million mistake. While at Harvard and in the stages of creating Facebook, Zuckerberg asked Green to drop out in order to help with the social network. Green did not drop out and it probably cost him millions and millions of dollars.

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