If someone suggested to you, 20 or so years ago, before podcasts existed, that a radio show should be on the internet what would you have said? At the time, an idea like that would’ve sounded pretty out-there, right?

Well in 1995 that happened to Dan Carlin, who is now a principal figure in the podcast world.

Carlin, host of the popular podcasts Common Sense with Dan Carlin and Hardcore History, was approached by one of his listeners, a computer programmer, about putting his show on the internet.

“His idea was to create some form of internet radio and have me as his poster child–for lack of a better phrase,” said Carlin. “It never panned out, but it planted the thought in my head that this was possible at some point in the future.”

In the late ‘90s Carlin started a company with some friends that was centered around amateur content creation and the idea rose again. For a while, he produced the podcast as a part of that company– then he left, and with him came the podcast. That happened in 2005.

Now, Carlin is one of the most renowned hosts in the space. Podcasting has become his full time occupation with his two shows: Common Sense with Dan Carlin and Hardcore History.

The two, he said, are completely different to produce.

“They are not comparable in any way. I can get a Common Sense out in a single sitting if everything goes well,” said Carlin. “I can’t get a Hardcore History out in less than four and a half months under any circumstances– and that would be a quick turnaround at that! That should demonstrate the magnitude of the difference right there.”

Common Sense, which he started first, is essentially the same show he was doing when he was on the radio, restructured to better fit the podcast medium. Carlin said the concept and approach were familiar, only the delivery mechanism was new. Podcasting gave him the opportunity to speak without constraints previously placed on him by the format taken by commercial radio.

Hardcore History though, was something new.

“My mother-in-law suggested I talk about history in a podcast,” said Carlin.

She brought up this idea because he was endlessly reading and speaking about history to family and friends and had already begun doing a podcast on current events. His response was that it wouldn’t be possible since he didn’t have the academic qualifications to teach history.

“She said ‘I didn’t realize that you needed a PhD to tell stories’. It was a bit of a light bulb-over-your-head moment,” he said. “It also dictated to me how such a show would have to be done. It wasn’t going to be designed as a history lesson. It was going to be ‘stories and concepts and ideas from history that Dan loves…for people who love history’.”

Carlin has always loved history. He received his Bachelor of Arts in the subject at the University of Colorado.

“According to my mom, I have been interested in history from the time I first could speak,” said Carlin. “I got my first history book when I was about 4. Lots of pictures! I still have it.”

It’s a good thing he has a ceaseless passion for the subject– as each show takes an enormous amount of work to produce. Since that is the case, he makes sure to choose topics that he has a little bit of background on.

“I need to know a decent amount about it,” said Carlin. “I can’t educate myself on a topic from a ground zero base of previous knowledge in the time-span between releases.”

He takes however long necessary to prepare for each episode, studying and reading, depending on what he is planning to cover.

“The more momentous the event–and the more vantage points there are, The First World War, for example, has histories printed from the perspective of every major participant… That right there adds to the research load– the more material there is to digest and incorporate,” explained Carlin.

The work is strenuous and takes all of Carlin’s effort to complete an episode– each time he approaches a new one.

“I always joke that I use every last brain cell on the latest release, and then need to exceed the previous standard with the next effort,” he said. “The marathon, as opposed to sprint, aspect of the content-creation challenge is something that must be dealt with. How do you give your all continually, while maintaining your ability to do it well again and again? It’s hardly my own concern though. Everyone who deals with making a living creatively has this same issue.”

Yet he continues to do it over and over– and has not stopped since beginning the show in 2006. At the rate they’ve been working currently, they have been producing about two Hardcore History shows each year.

“So…it’s taking forever basically,” said Carlin. “Hopefully we end up with a better final version after all that work.”

The team that’s working on the podcast is extremely small. Carlin likes to keep a small team on the show. He said he’d rather not run a firm with employees to manage and prefers to focus on the work itself.

This focus makes it a full time occupation, which is something not too many independent podcasters can say about their show– and monetarily, Carlin has a specific structure to keep it this way. His shows, some of which are as long as six hours which makes them a little different than other podcasts that usually span a time of around 15 minutes to an hour, so the monetization process is a little different as well.

“Well, other shows often charge money to gain access to their past content in aggregate behind a paywall,” he said. “This is a logical system or model for content that is akin to a magazine or newspaper in terms of how it is consumed. But these Hardcore History shows are more like books, or record albums in terms of the model that best works for them. They all have a stand-alone, evergreen aspect to them and so we treat them more like books.”

To do that, they keep the episodes available for free for several years after their initial release and then send them to the archives. Each episode is treated as an individual property rather than an episode to a larger whole unless it is a part of one of their larger series’. Selling the older shows, Carlin said, is their most profitable source of income. They do however, do some ads on the show– though that’s not enough since they don’t release shows regularly.

The podcasting space has changed a great deal since Carlin started working in it more than a decade ago.

“I did (broadly) predict/foresee the way it has evolved up to now back in the late 1990s/early 2000s when I was pushing the amateur content idea on very skeptical venture capitalists,” he said. “This modern reality was sort of what I was trying to sell them on. But where it will go from here is not at all obvious to me.”

Carlin, regardless of how the podcasting world continues to develop, will surely remain a staple in the podcasting world as fans clamor to listen to his latest release and are willing to pay for his archived content.