“This American Life” is 10 years old, and it has changed public radio. “The program has become a full-fledged brand, complete with a pair of movie projects, a record deal with Shout! Factory and a television version of the show awaiting a green light from cable’s Showtime channel. Few thought Glass’ quirky, narrative-driven radio hour would have either the impact or the longevity it has enjoyed. The show’s episodic style tied together by the host’s soft-spoken narration was initially a tough sell.”