The Golden Age of Podcasts, i.e. when it was possible to hear almost anything you want for free, may be ending as an increasing number of top podcasts go behind the paywall.

One of the first big name programs to make the leap is David Axelrod’s Axe Files, featuring a broad selection of media, political and entertainment industry guests in deep, hour-long chats. The show will play exclusively at Luminary, a company backed with $100 million in venture capital funding and dedicated to becoming the “Netflix of podcasting.” Luminary has also pulled in some other big names in the podcasting world, including Malcolm Gladwell, Guy Raz, Leon Neyfakh (“Slow Burn”) and others. If you want to listen to these, even one of them, it’s going to cost $8/month.

It’s understandable why this day has come. Podcasts are following the seemingly inevitable path to monetization when advertising doesn’t cut it. Of course, we saw what happened to the newspaper industry when it was too slow to control access to its product.

Given the marketing dollars projected to move to podcasting in the next few years, it’s important for us as marketers to keep an eye on this.