Bill Simmons spent the first part of his career reinventing sports writing on the Web. Then he decided to try something hard.

Since 2007, ESPN’s star personality has been one of the most prominent champions of podcasting, the audio version of blogging. It’s a medium that was supposed to be a big deal 10 years ago, then fizzled out, but is finally starting to look ready for prime time.

Simmons can claim at least some of the credit for that. For the past seven years, he has used his pulpit — first at ESPN.com and now at the Grantland site he had ESPN build for him — to expose a very broad audience to the concept of audio downloads, which they can listen to wherever they want, when they want.

Simmons’s podcasts are pretty good analogs of his columns: Smart-funny, smart-obsessive, drenched in pop culture and digressive in a way that seems easy to mimic but isn’t. He’s got enough stature to command interviews with both Larry Bird and the president of the United States. But his most enjoyable ones are often recurring chats with all-but-anonymous college pals like John “JackO” O’Connell.

http://www.youtube.com/watch?v=4vcvRJeIZu4

Simmons’s fans seem up for it. Last year, listeners downloaded episodes of his signature BS Report 32 million times, and downloaded another 19 million podcasts featuring Simmons’s Grantland contributors, like former NBA star Jalen Rose.

This would normally be the sentence where I tell you how much those numbers have grown in the last year, but podcasts and consistent metrics don’t seem to like each other very much. Apple, which would have the best sense of actual download numbers from its iTunes store, doesn’t release them. And third-party podcast counters end up changing methodologies — full downloads? partial downloads? auto subscriptions? on-demand requests? — all the time.

That uncertainty extends to the business of podcasts, too. As with other digital media, ad money hasn’t followed users, which means that even very successful podcasters often use their shows as something other than revenue-generators — like promotions for comedy tours, or stepping-stones to sitcom deals.

In 2009, when I wrote about Adam Carolla, another podcasting king (and, not coincidentally, a friend of Simmons’s), an ESPN executive told me that podcasting was a “seven-figure-plus” business for the sports giant — that is, a rounding error. Today my educated hunch is that podcasting, including Simmons’s work, remains a seven-figure business for ESPN.

I don’t mind the fact that podcasts are still a medium that has yet to be colonized by the ad guys. It keeps things low stakes, which means there’s plenty of room for experimentation, and allows for labors of love. That’s great for me, the non-paying listener.

But one way to boost podcasts’ commercial prospects is to transform them into something else. Simmons, like a handful of other ambitious podcasters, has been pushing into video over the past few years, by trying to record an audio and video segment at the same time.

The results are getting pretty good. Check out this recent clip with Rose, which features a clever use of YouTube’s annotations feature to create an on-demand selector for different segments:

http://www.youtube.com/watch?v=uZjm3KSHt-g

You’ll see more of this experimenting — on behalf of listener/viewers, as well as advertisers — to come, according to Simmons. “The big goal is to make this a business,” he said. “[To] try as much stuff as we can, and figure out what people will want to buy. ”

Here’s an edited excerpt of a chat I had with him about his podcasting career, and ambitions:

Peter Kafka: You established yourself as a star Web columnist way before you got into podcasting. Why did you decide to branch out?

Bill Simmons: ESPN had some NBA podcast. I didn’t know what that was, but [former Celtics star and current executive] Danny Ainge was on it, and it was heading into the lottery and all that stuff, and I wanted to know what he was talking about. So I clicked on it, and it was like this long radio interview that was really easy to listen to.

The guy who did it — I think it was [ESPN reporter] Marc Stein — it sounded like he was doing it on a phone. And I was like, “What the hell is this? This is interesting.” So I did a little research and I just decided I wanted one. I think Marc Stein was my first guest. I was doing it from my old house, on some weird contraption they mailed me.

I think the second one I did, [radio-broadcaster-turned-podcaster Adam] Carolla came over. I didn’t have the right equipment, so he had to be on the phone, but he was at my house, in another room. It’s really come a long away.

It’s been probably one of the best things that could have happened to me, just from the standpoint of getting reps. I don’t even know how many I’ve done at this point. I’m actually a pretty good interviewer — I didn’t know.

But it’s not just interviewing people. A lot of your podcasts are you talking to your friends.

The one thing I knew I wanted to do once we got going, was my buddy Sal and I had always guessed the [NFL gambling] lines on the phone on Sunday night. He would call me, we’d guess the lines, we kept track. I always felt like that would be a great radio show. So once the podcast got going, I was like, “That’s definitely going to work. People are going to like that.”

I did one really bad podcast the first year, with [Nascar driver] Tony Stewart. Initially, you think you want to get really big guests, huge guests. But what you realize is, you have to have some sort of common ground with who you’re talking to. At least I do. I need to know what they do. I’m trying to talk to him about Nascar. I don’t care about Nascar. He could tell I don’t care. That was a good learning experience for me.

So I made my friends characters in the podcast. I would call my buddy JackO, who’s a big Yankees fan. I would call him, and we’d argue Yankees/Red Sox. I would call Sal. Lately I’ve been calling my dad, who just retired.

I don’t really like baseball, and I don’t like the Yankees or the Red Sox, but I’ll end up listening to you and JackO talk, anyway.

My whole thing is you have to have chemistry with a person, because you can’t see them. And it’s really hard to do an interview or talk to someone when you can’t see them. If there’s any kind of awkwardness, on a podcast, it feels 100 times more awkward. So I always try to gravitate toward people that I feel like I’m going to have chemistry with.

Did you spend a lot time listening to radio as a kid?

Obviously in Boston, growing up, Eddie Andelman was a giant. And Mike and the Mad Dog. I loved the way those guys interacted. I felt like they were my friends. They could talk about anything. The best ones they would do was when they talked about the Oscars. So as the podcast developed, that dynamic was always in my head — to sort of emulate those guys.

You mentioned getting reps, and now you have a TV job. Was the idea to use podcasting as a training ground?

Not at all. The one thing I’ve tried to do over the years is try to go where I thought things were going. And in ’07, it just seemed like a really cool thing, and I felt like I could get ahead of it a little bit. There wasn’t a lot of people on the corner.

I got all these reps the first two years, when a lot of people didn’t even have iTunes yet, and people were listening on ESPN.com files. Podcasts didn’t really take off as a medium, I don’t think, until the fall of 2009, maybe even a little into 2010.

Because it was much harder to promote. Now people have Twitter and Facebook, they can push their podcasts. But those first two years for me were a real advantage on ESPN.com, because they would promote them.

Carolla has been one of the pioneers. He didn’t really have one until late 2009. He did mine all the time. And I could tell — his wheels were always turning, he was always asking questions. How much is the equipment? And then when his radio show fell apart, he didn’t panic. He was like, “I’m forming a podcast network” — he could see the potential of it, too. I think a lot of people who were in there early could see it.

http://www.youtube.com/watch?v=xUNafDOkg4k

Now there are so many of them. It’s really hard to stand out. I’m lucky enough to stand out just because I was there so early. There’s only so many hours in the day. I think what happens is people have there three or four podcasts that they listen to, and that’s it. And a lot of them are real niche.

Mine tries to be broader. I try to hit a lot of different sports, and do Oscars and TV. I want to appeal to as many people as I can with it. But a lot of other people have gone the other way, which I think is smart. You want to grab the diehard people. And that’s what we have with the Grantland Network podcasts.

Was there a point where you realized you had broken through?

I never really totally knew it was going to take off — they always told me, people were listening to them, and blah blah blah, but you never really know — until I was at All Star Weekend in Phoenix, in 2009. I was standing outside the hotel, waiting for a cab. And this jogger was running toward me, looking at me like I was an alien. He had headphones on. And he pointed at me, and pointed at his headphones. I didn’t know what the hell he was doing. And he says, “I’m listening to you right now! On the podcast! Like you’re right there, and you’re…!”

And I was like “Ohhhh.” So I did a little research on it, asking people how they listen to it. What you realize is, people listen to them when they work out, people listen to them when they’re commuting. When they’re in their car. When they go on a road trip, they download six hours of them. When I found that out, I was like, “Oh, this is great for me. This is definitely going to make it, because that makes sense to me.”

Did you get pushback from ESPN about the business potential of podcasts?

[Laughs] I could really get in trouble here.

I was extremely disenchanted with the way they regarded podcasts for a long time. I don’t think they saw it at all. And there were a lot of emails that were sent over the years. I couldn’t believe it took me three-and-a-half years to get a sponsor.

Because it’s like: We know who’s listening to it. People are clicking on it. We have an ad that plays at the beginning of it. How is that not sponsorable? But the reality is, they’re trying to get people to buy ads, and the people who are spending that money are people who didn’t understand the medium.

What I realized is advertising companies are usually four to five years behind whatever is cool. That’s just the way it is. And it wasn’t until 2011, 2012, that shit really started happening with podcasts. A lot of it was people finally started writing about Carolla and Marc Maron, and me, and whomever, and those articles get passed around, and people at the companies who are spending the ad money are like, “Oh! So this is a thing!” And that’s when stuff happens.

And now you’re turning a lot of your audio podcasts into videos, too.

For us it’s a great thing. When I was figuring out Grantland, and what it was going to look like, podcasts were a huge part of it. Because I knew the potential better than anybody. I wanted to have a whole bunch of them. We brought in Dave Jacoby, who’s in charge of all my video and audio stuff, who’s been on my podcast a million times, who’s really smart, and we came up with plan for how to do it.

We have this state of the art podcast studio we built, with a Tricaster camera. It’s a converted electrical closet in LA Live, and it’s intimate. We wanted a place that people could come into, and I could do an interview with them, but they wouldn’t feel like they were being filmed.

You’re sitting there for a minute and you just feel like you’re talking to me, you don’t even feel like you’re on camera. We’ve done some really good stuff in there. We had Louis CK, and athletes and all different types of people.

http://www.youtube.com/watch?v=bPVEO6yG-L8

We always saw that the potential of the podcast was beyond just iTunes and ESPN.com. We wanted it to be something that if you wanted to watch it on YouTube, you could. We want people to experience it however they want.

The big goal is how do make this a business. Like, is this something where we could get the studio sponsored? Could we have the BS Report studio, sponsored by X? Do we have people buy the BS Report, do we have them buy all the Grantland Network podcasts? Can we split them off individually? And what we figured out is, try as much stuff as we can, and figure out what people will want to buy.

You were going to interview Barack Obama, and then you didn’t, and eventually you did. And you’ve interviewed your hero Larry Bird. Do you have a favorite podcast guest?

The Obama one was really disappointing. I’ll never get over that. I get the reasons why we couldn’t do it. But we could have interviewed him in 2008, when I don’t even think he had won the nomination yet, and it was at a time when podcasts weren’t a thing, you know? It easily would have been the biggest podcast of all time. Nothing would have compared to it. So that was frustrating. But the fact that we finally ended up getting him was pretty cool.

And before we built the studio, I used to have people come over to my house. And I’ve had some great ones in my house. Which is its own weird thing. Sometimes you do an interview with somebody, and you just kind of have a moment. Where you kind of go, “This is awesome. People are going to really like this.” And the weird part is that it’s just happening at your house.

But I would say Bird was the highlight. I’m ashamed to admit this, but I was more excited for Bird than Obama.

Do your highlights correlate to your audience’s? Is the stuff that you like the stuff your audience likes the most?

I just feel like, as long as I care, we’re okay. It drives Jacoby crazy, but I turn down a lot of possibilities. Because I would never want to do one where people could tell I wasn’t into it. I think people can tell. It’s such a naked format.

Even if I’m hosting a late-night TV show, and I have an audience, you can fake not being interested in a guest. But when you’re just having a conversation, it’s too easy to tell.