The New Yorker's John Cassidy talks about how keeping Ezra Klein might not have made sense profit-wise for the Washington Post. He does some back of the envelope calculations to estimate the revenues from Wonkblog:
"That translates into revenues of a hundred thousand dollars per month, or $1.2 million a year."
Many of these Wall Street Guys make that in less than a day. This shows you the incredible positive externalities of good journalism, and negative externalities of much of finance.