Jason Hirschhorn talks with Peter Kafka about his past jobs at Viacom, Dish Network and MySpace and at his new startup Redef. Expanding on the Redef Media email newsletter, which Hirschhorn started in 2006, Redef now has more than 50,000 subscribers in several industries, including music, fashion and sports. He also talks (in great detail) about his quadruple bypass surgery and how Redef's fans saved his life when his doctors were confounded by complications.