Vox Media publishes many articles that get people talking. But now the company is doing something it hopes will get its consumers to listen – even when its journalism and analysis aren’t at the center of the conversation.

Listeners to Recode’s “Recode/Decode” podcast this week may have been surprised to hear host Kara Swisher take a break from the program and start to interview Russ Hanneman, the erratic technology investor from HBO’s comedy “Silicon Valley.” In the exchange – laden with profanity – Swisher quizzes the fictional character (played by actor Chris Diamantopoulos) on his efforts to launch cryptocurrencies, which is one of the current plotlines of the program. The interview will also be heard on The Verge’s “Vergecast” and Recode’s “Recode Media.”

“As advertisers, we’re attracted to podcasting due to the undivided attention of its consumers,” says Dana Flax, director of digital and social media at HBO, in responses that were sent via email. “As storytellers, we love the ability to extend the ‘Silicon Valley’ narratives into the real world and surprise and delight our fans.” The podcast segment is bookended by language that says it’s sponsored by HBO.

Marketers are starting to turn up the volume when it comes to podcasts. New availability of content in so-called “connected cars” is turning a format that was once something akin to a ham radio operator shouting into the wind into a media venue that is gaining more scale and distribution. “While it only commands a tiny chunk of the overall marketing pie, podcast advertising is growing at an exponential rate, in large part due to its effectiveness,” notes Matthew Stefl, a marketing professor at Loyola Marymount University in Los Angeles. “You can’t find an episode of ‘Radio Lab’, ‘Stuff You Should Know,’ ‘Criminal’ or ‘99% Invisible’ without the show host giving the brand a friendly, and enthusiastic plug for Blue Apron, Mailchimp, Drop Box or Purple Mattress.”

No one will confuse a single podcast for the next “Sunday Night Football,” mind you, but Edison Research earlier this year found weekly podcast listeners typically listen to seven of the programs each week, compared with five in 2017. The market-research firm also found that 26% of people aged 12 and older listened to a podcast in the last month.

Vox Media, like many other media outlets, has long run commercials in its podcasts. In recent months, however, it has tried to bust old models, like having the podcaster offer a personal endorsement or naming the sponsor at the end of the program. Some advertisers have even launched their own full-length podcasts, setting up promotional programs against ones whose aim isn’t necessarily to sell recipes on demand or assistance with email distribution.

“The idea of short-form customized audio content that lives within the show is new and novel,” says Evan Lang, vice president of revenue and partnerships for Vox Media’s audio division.

Some podcasters – particularly “micro-producers” who aren’t part of an established media brand – may be tempted to blur the lines between the program and the clever advertising, suggests Anthony Miyazaki, executive director of marketing and analytics at the Florida International University College of Business. They “sometimes don’t know the rules, and also don’t think that the rules apply to them,” he says.

People who hear the HBO ad during the Vox podcast should catch on very quickly. The loose language sort of gives things away, as do the character’s rants provided in response to Swisher’s questions. “Kara, this town is filled with a—holes getting rich off crypto by doing jack,” says Hanneman. “The Winklevoss twins put in loose change five years ago. Now they are bitcoin billionaires. So yeah, I’ll put in some loose change to take that f—–g ride.”

HBO recently sparked attention by setting up a facsimile of the fictional town that is the center of its drama “Westworld” outside the South by Southwest Festival in Austin Texas. Vox Media executives noticed that, and set about pitching the Time Warner premium programmer on the idea of “custom segments” in its podcasts, says Lang. “They came to the table with the idea of bringing talent and really tying it to a specific episode. It’ not just this disparate piece of advertising.”

Vox Media already had a loose affiliation with the program. Swisher, the larger-than-life technology journalist, has appeared as herself on the series a handful of times.