(Bloomberg) -- On Sept. 18, HBO Max launched “Batman: The Audio Adventures,” a new, scripted podcast featuring several prominent actors playing characters from Gotham City. The majority of the 10-episode audio series will be available exclusively on HBO Max.

Welcome to the new, escalating front in the streaming wars.

Joshua Walker, chief strategy officer at AT&T Inc.’s HBO Max, described the Batman podcast, which stars Jeffrey Wright, Rosario Dawson and John Leguizamo, as an experiment. 

“We’re taking a test and learn approach,” Walker said in an interview. “If our fans tell us this is content they want to see more of then we’ll increase the investment.”

Across the fiercely competitive landscape, other streamers are also taking podcasts more seriously. In July, Netflix Inc. hired a former Apple Inc. executive to run its podcasting business and has discussed making original, standalone podcasts that could be adapted into new TV series. At the same time, Amazon.com Inc., the owner of Amazon Prime Video, has been stepping up its investment in the field as well.  

In April, Apple TV+ released a six-part nonfiction podcast that delves into the story of U.S. Navy SEAL Eddie Gallagher, who was charged with committing war crimes before being acquitted on all but one minor charge. The podcast, which is hosted by Dan Taberski, will be joined this fall by a documentary series on the same topic.

In the past few years, HBO Max and its rival, Netflix, have been building a growing portfolio of what are called companion podcasts — a form of marketing in which the hosts discuss, promote and analyze in depth a new original series from the streaming service or a related genre.   

“They’re about driving awareness about a particular show and giving our fans a way to go deeper into the story,” Walker said.

Companion podcasts can be especially useful for HBO Max, which unlike Netflix, typically releases episodes of shows on a weekly basis and needs ways to keep fans engaged. Among subscribers, listeners of HBO Max podcasts watch more than twice as much programming on the service as those who don’t.

“That’s what driving us to increase that investment,” Walker said.For the likes of HBO Max, Netflix, Amazon and Apple TV+, podcasts could soon evolve into something more than just promotional tools for existing shows — the format could also become a testing ground for new ones.

“They could turn a script into an audio drama and if it generates enough interest then they feel like the risk has been mitigated enough to spend $20 million on a show,” said Nick Quah, a podcast critic at Vulture. “It makes a ton of sense.”

If streaming services want to begin using podcasts the way NBC and CBS use pilot episodes, Quah said, they could acquire a company like QCode, which was started in 2019 by a former agent with Creative Artists Agency. QCode specializes in creating podcasts starring celebrities, which often seem tailor-made to be adapted into TV series and movies. Two of QCode’s podcasts, an erotic drama called “Dirty Diana” starring Demi Moore and a sci-fi mystery entitled “The Left Right Game,” are being turned into shows by Amazon.

“QCode seems like it’s well-positioned to be that thing for streaming platforms when they want to take this seriously,” Quah said. “I don't think streaming platforms are going that route with an audio project yet, but I think they’re going to get there.”

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