Source: http://nymag.com/daily/intelligencer/201...

 Around 2009 or 2010, the podcast scene seemed to wither. The stalwarts ("This American Life," "Radiolab") stayed around at the top of the iTunes charts, but there wasn't much else happening. Download numbers fell. Interest waned. People moved on to online video and streaming music services as a way to pass the time.

Today, a very different problem exists: There are too many great podcasts to keep up with. There's "Serial," the true-crime drama hosted by "This American Life" producer Sarah Koenig. There's "99% Invisible," a design-themed podcast hosted by Roman Mars that has run several mega-successful Kickstarter campaigns. There's "StartUp," another product of the public-radio diaspora, which tells the episodic story of NPR veteran Alex Blumberg's attempt to create a podcasting business. Then there are the celebrities: Ice T, Snooki from Jersey Shore, Stone Cold Steve Austin — podcasters all. According to Edison Research, 39 million people listened to a podcast in the last month, the highest number on record.

What's happening? And why now? The word podcast is roughly ten years old, after all, and the "pod" to which it refers has been discontinued. Still, the genre seems more alive than ever. I spoke to the people behind several popular shows, and they agreed: We're in a golden age of podcasting.

....

Another reason that podcasts may be growing is that the economics are compelling. Producing an average podcast costs far less than producing a TV show or a radio show (all you really need is a microphone or two, a copy of Audacity or some other editing software, and a cheap hosting service for the audio files themselves). And the advertising rates on a successful podcast are big enough to pay for the costs many times over. Several top podcasters told me that their CPM (the cost to an advertiser per thousand impressions, a standard ad-industry unit) was between $20 and $45. Compare that to a typical radio CPM (roughly $1 to $18) or network TV ($5 to $20) or even a regular old web ad ($1 to $20), and the podcast wins. Podcasts can charge higher ad rates because of the personal nature of the single-host format — as an advertiser, it's far better to have "Serial"'s Sarah Koenig reading your copy out loud than to burst in with a prepackaged ad that nobody will pay attention to.

But as I talked to podcasters, they told me that the biggest reason for the podcast renaissance has nothing to do with the podcasts themselves, or the advertisers funding them.

It's actually about cars.