The lesson I think I've learned --- as late as I am in getting around to it --- is that not every person (editor, producer, agent, etc.) asking you to write something for little or no compensation is a crook looking to exploit you. Sometimes, the risk of writing for free is one well worth taking.
The Nate Thayer/Atlantic piece that got the ball rolling is here:
From the Atlantic:Thanks for responding. Maybe by the end of the week? 1,200 words? We unfortunately can’t pay you for it, but we do reach 13 million readers a month. I understand if that’s not a workable arrangement for you, I just wanted to see if you were interested.