XM Satellite Radio's CEO on Growth and the Medium XM Satellite Radio has added more than a half million subscribers in the last 3 months and shares of XM have quintupled over the last 2 years. Can XM continue its meteoric growth? When will satellite radio become profitable? Is there room for both XM and rival Sirius? David talks about the out-of-this-world business of satellite radio with XM CEO Hugh Panero.