WILLIAM BRANGHAM: But first to the world of audio.

An estimated half-a-billion people will listen to podcasts this year.

That's the most in the medium's short history.

Since the very term podcast was coined 20 years ago, the format has grown into a $25 billion industry.

Spotify just revealed that its top-performing podcast from Joe Rogan has over 14 million subscribers.

That's nearly three times the next most popular show.

But the industry's growth has also come with major growing pains.

Jeffrey Brown reports for our arts and culture series, Canvas.

JEFFREY BROWN: It was a celebration of an industry, the annual On Air Fest, a showcase for and gathering of the world of podcasting, held, of course, in a hip Brooklyn hotel.

The first session marked the 10-year anniversary of the podcast that changed everything, Sarah Koenig's and Julie Snyder's "Serial."

How many people have downloaded the first season?

Do you know?

WOMAN: Oh, probably more than 200 million.

JEFFREY BROWN: In fact, "Serial" has over 300 million downloads to date.

And it thrust this medium into the cultural mainstream.

Today, On Air Fest is a launchpad for new shows.

WOMAN: You are about to get a first listen of her new limited series.

JEFFREY BROWN: A gathering place for industry heavyweights like Malcolm Gladwell and even a platform for celebrities from other fields, like Grammy Award-winning singer-songwriter Norah Jones.

Why are you here?

NORAH JONES, Musician: I guess because I have a podcast now.

Doesn't everybody?

JEFFREY BROWN: It can certainly sound that way, with mega-popular talk shows like Joe Rogan's provocative interview podcast.

ELON MUSK, Owner, X: I mean, it's legal, right?

JOE ROGAN, Host, "The Joe Rogan Experience": Totally legal.

ELON MUSK: OK. JEFFREY BROWN: True crime.

WOMAN: And she walked into something she never expected, a trail of blood.

JEFFREY BROWN: Music, art, even cooking shows.

MAN: Cooking is a philosophy, unless it's pastry.

Then its chemistry.

JEFFREY BROWN: Everything for everyone.

But if you lean in and listen closely, there's another story still unfolding, a tale of two worlds.

Scott Newman, founder of On Air Fest, brought them together here in Brooklyn.

SCOTT NEWMAN, Founder, On Air Fest: You have an industry that is an opportunist commercial industry around an art form.

So everyone with commercial interests is looking to take advantage and play the game.

LAURA MAYER, ABC News: I started my first podcast-podcast in 2008, when I was still in college.

JEFFREY BROWN: Today, Laura Mayer is executive producer of audio at ABC News, and host of her own podcast, "Shameless Acquisition Target," a show about her own experiences within the industry as media giants took notice and became major players.

LAURA MAYER: In 2019, there was a shot across the bow.

JEFFREY BROWN: That's when streaming giant Spotify bought production company Gimlet Media, an industry leader, for an enormous sum.

LAURA MAYER: The amount was for north of $200 million.

And I can remember being like, oh, no.

JEFFREY BROWN: I mean, the world has changed.

LAURA MAYER: The world has changed.

JEFFREY BROWN: And enormous money has come in.

LAURA MAYER: Yes.

But then these larger companies that had been intending to scale saw that they weren't getting their return on investment.

And then you saw in the past I'd say a year and a little bit huge, huge, huge rounds of layoffs.

JEFFREY BROWN: The headlines have been grim.

KELLI HURLEY, Vice President and Head of Revenue Partnerships, SiriusXM: I think there was a little bit of over excitement.

And a lot of people wanted to get into the medium quickly.

JEFFREY BROWN: Because they felt they just had to be there.

KELLI HURLEY: Absolutely.

And I think that it was a little bit of an arms race.

JEFFREY BROWN: Kelli Hurley, V.P.

and head of revenue partnerships at SiriusXM, one of the majors who jumped in, says Sirius remains serious about podcasting, but: KELLI HURLEY: I think we're being a lot more rigorous in terms of the deals that we're bringing in.

JEFFREY BROWN: Rigorous means you're looking to see what will make money?

KELLI HURLEY: Absolutely.

JEFFREY BROWN: Part of that rigor, laying off hundreds of employees in the last two years, including in the podcasting department, among them, longtime audio producer John DeLore.

Like many who came out of the tradition of public radio, DeLore had high hopes that the investment by Sirius and others would bring creative freedom, time, and resources.

JOHN DELORE, Co-Founder, Audio Flux: Ultimately there was just a misalignment of their strategy, if they had one, but between really what kind of audio they wanted to make in that space.

You know, this is a company that their bread and butter is Howard Stern.

And so the kind of stuff that we make is -- requires a lot of time.

JEFFREY BROWN: After the layoffs, DeLore co-founded a small independent company called Audio Flux with producer Julie Shapiro.

JULIE SHAPIRO, Co-Founder, Audio Flux: Audio Flux is a new home for independent audio and new voices and an engine for community in audio and big ideas in podcasting.

JEFFREY BROWN: What does that mean?

JULIE SHAPIRO: It means that the podcasting world has become very corporate and moneyed, and imagination has left the building.

And we're just trying to say, like, there is a space to, like, think through these things, feel the pieces, play with the medium and try something new.

JOHN DELORE: And I think there's an audience for the kind of experimental, craft-driven stuff that we believe in, that we care about.

It is just that we need to bring them new things that they will want to hear.

JEFFREY BROWN: Those niche audiences, Laura Mayer says, do exist and can be valuable.

LAURA MAYER: The audience is more fragmented, perhaps, on a per podcast basis.

However, those audiences are loyal.

JEFFREY BROWN: Can both things be true, that the audience continues to grow, but it's still a very difficult business model?

LAURA MAYER: The audience will continue to grow, but I think the business model is being right-sized right now.

You know, the obsession with scale in terms of making the one show that everyone listens to, that may not be the case.

JEFFREY BROWN: Tonya Mosley, co-host of NPR's "Fresh Air," is speaking to one audience in particular with her new podcast, "She Has a Name," which she launched here.

TONYA MOSLEY, Co-Host, "Fresh Air": This is more than trying to solve a cold case.

It's about a family in search of healing and a city fighting for its own survival.

TONYA MOSLEY: I'm talking specifically to people, Black and brown people from urban centers who understand this story.

And everyone else can follow along if they want to, and they can be a part of this too.

Well, where are they?

Where can I capture their attention?

JEFFREY BROWN: You are reaching out to a new audience in that sense?

TONYA MOSLEY: I hope so.

I mean, at this point, we don't have a template, we don't have a blueprint.

So we have to try new things, and also try things that we know have worked in mainstream media.

JEFFREY BROWN: On the business side, Kelli Hurley of Sirius also sees new opportunities.

KELLI HURLEY: We're going to see content creators expand beyond audio and become true influencers.

That can mean all forms of social media.

That can mean YouTube content, video content.

That can even mean a live event, a tour.

JEFFREY BROWN: On Air Fest founder Scott Newman believes the future is still being written.

SCOTT NEWMAN: It's going to be the people that are here that are going to decide what the future is, through their action, through their investment, through their creative work.

JEFFREY BROWN: As for musician Norah Jones.

NORAH JONES: I mean, I'm not going to quit my day job.

It's more of a labor of love, and it's fun, and it's just, like, joyful.

JEFFREY BROWN: For the "PBS NewsHour," I'm Jeffrey Brown at On Air Fest in Brooklyn, New York.