Both XM Satellite Radio (NASDAQ:XMSR) and rival Sirius Satellite Radio (NASDAQ:SIRI) have seen their stocks tumble recently. Will a merger improve their reception on Wall Street? And what is the future of radio? How much of a threat is Apple's (NASDAQ:AAPL) iPod? In this installment of "Fool Video," I ask best-selling business author Seth Godin, author of The Dip: A Little Book That Teaches You When to Quit (And When to Stick).