The transformation of podcasts from a niche audio format to a linchpin of celebrity press tours is complete. Taylor Swift has finally appeared on one.

Her guest spot on “New Heights,” a video podcast about football and pop culture co-hosted by her boyfriend, Travis Kelce, amassed nearly nine million views in about 12 hours on YouTube, setting a record for the show and cementing its place among modern media properties. About 1.3 million people tuned in simultaneously to a livestream of the episode before it was felled by a technical glitch.

By comparison, an October episode of “The Joe Rogan Experience” with President Trump reached about 11 million views in its first 12 hours on YouTube.

Released on Wednesday night, the “New Heights” episode served as a long-form album announcement for Ms. Swift, who has never taken a particularly traditional approach to delivering such news. When not dropping surprise albums, she has opted for announcing albums on tour stops, on Yahoo livestreams or in the middle of awards shows.

Rarely does Ms. Swift sit for an interview. (Exceptions include in-depth conversations about songwriting for Apple in 2020, and about directing for Variety in 2022.) That her first proper podcast interview was conducted beside her romantic partner speaks to both her personal reluctance to engage with mainstream media and a larger truth about podcasting: For prominent figures, it has become a friendly space, where unchecked conversation can flow freely.

Silicon Valley founders and White House officials have embraced two- or three-hour conversations with Mr. Rogan. Athletes and musicians talk about their mental health on “Armchair Expert With Dax Shepard.” The actor Jason Momoa just made his podcast debut on “SmartLess,” disclosing a near-drowning, while Dakota Johnson chose to make her debut on “Good Hang With Amy Poehler,” holding her new puppy in her lap.

“Not only do these podcasts have massive reach, but they’re also places where you can have a very nuanced, long-form conversation,” said Josh Lindgren, head of podcasts at Creative Artists Agency, in an interview on Wednesday. “The editing tends to have a fairly light touch, and so it’s a place where you can go and have a conversation and expect that that’s more or less what’s going to get transmitted to your audience.” (CAA represents some of Mr. Kelce’s business.)

While these interviews may seem journalistic in nature, most stars of new media do not consider themselves journalists. In their celebrity interviews, they reject the blunt questions of 1990s network broadcasters and the literary sensibility of 1970s magazine scribes. They foster a sense of safety. Their goal is intimacy, not necessarily accountability.

“We’re not a ‘gotcha’ show,” Michael Bosstick, chief executive of the podcasting network Dear Media, told The New York Times this year. He and his wife interviewed Ivanka Trump, the elder daughter of President Trump, in her second podcast appearance; her first was with Lex Fridman, a podcaster focused primarily on science and technology, whom Ms. Trump described as a “friend.” Neither show was a places where Ms. Trump would have expected to be grilled on her father’s policies or her role in shaping them.

“It’s about making the guests feel comfortable that we’re going to actually let them tell their story,” said Mr. Bosstick, who spoke to Ms. Trump about skiing, workout supplements, her morning routine and her interest in A.I.

Alex Cooper, the host of “Call Her Daddy,” told The Times last year that when interview subjects arrived at her studio “terrified” that the internet would pick apart their words, she reassured them that “we’re good” and “it’s chill.” Sean Evans, the host of “Hot Ones,” told Vulture in May that he believed his show should be an “extension of the guest,” assuring one actor that he was in “safe hands” while eating spicy wings.

“I would assume talent gets bored doing the traditional press junket, so this feels fresh and exciting,” said Kareem Rahma, host of “Subway Takes,” who has interviewed guests including the actress Cate Blanchett and Zohran Mamdani, New York’s Democratic candidate for mayor, while riding the city’s transit system. “From a more practical perspective, the average American spends seven hours a day looking at their phone, so it makes sense to meet the audience there.”

Much energy has been devoted to positioning internet-native shows like “Hot Ones” or “Subway Takes” as the new version of late-night talk shows — a long-declining format — particularly in terms of the clamoring by celebrity publicists to book their clients. (Mr. Evans has also been public about his desire for a prime-time Emmy statue.)

But late-night television appearances have always been short and sweet, marked by canned anecdotes or contrived games. Even glossy magazine covers, once pursued like a golden ticket by publicists, have lost some of their appeal.

Agents are still eager to see their clients swathed in high-fashion brands and shot by big-name photographers, but podcasts are simply “much quicker to execute, and they offer the talent the chance to speak in an unmediated way,” said Charlotte Owen, the editor of Bustle, which publishes both podcasts and more traditional cover stories.

But to Ms. Owen, who hosts “One Nightstand,” a podcast on which guests talk about their favorite books, it is not only celebrities who benefit from these lengthy video interviews.

“I’m often having more robust, intimate and revelatory conversations than I do when sat in a restaurant with a voice recorder between us,” she said. “And for guests, it’s like being in a batting cage for an hour. You’re going to hit something in that time.”

“New Heights” will certainly benefit from Ms. Swift’s appearance at a crucial moment for the podcast. Last year, Wondery acquired the rights to distribute and sell the show’s advertisements, negotiating a reported $100 million deal with Mr. Kelce and his co-host, his brother Jason. But this month, Wondery was broken up by its parent company, Amazon. The Kelces have since been funneled into a new department, Creator Services, as the company focuses less on traditional audio podcasts and more on deploying its splashy video-friendly talent across its platforms.

Before the episode’s release, after days of teasing the interview with Ms. Swift, “New Heights” reached No. 1 on Apple Podcasts’ chart. It had held that spot before, but not consistently.

Previously, the brothers’ most-watched YouTube video had about 8.6 million views. That was an interview with Jason Kelce’s wife, Kylie.