One podcasts rocket rideWhen the first episodes were posted in June 2012, they barely generated a ripple. “At the time, I don’t think I could even get my mom to listen to the podcast,” Mr. Baldwin said. “She was like, ‘Oh, another nonpaying job, that’s great, sweetie.’ ” They kept at it, posting a new 25-minute episode every other week. Over the next year, the show was downloaded roughly 150,000 times. Then, for reasons its creators still can’t fully explain, the audience exploded overnight. In July 2013, the show was downloaded 2.5 million times. It shot to the No. 1 spot on iTunes, surging ahead of popular programs like “This American Life” and “Radiolab.” That August, it was downloaded 8.5 million times. Rabid fans were obsessively dissecting each episode on sites like Reddit and Tumblr.