Podcast hosts are the influencers of the media industry, and advertisers in the $3.7 trillion dollar wellness industry have taken notice.

For wellness brands, podcast ads facilitate the introduction of concepts that need a bit more explanation. “Having a host explain how our products work, what ingredients go into them and why listeners should consider them is hugely valuable,” said Alex Friedman, co-founder of feminine care brand Lola. “Also, in most cases, reproductive health products aren’t inherently visual the same way clothing or beauty is, so they lend themselves really well to an audio medium.”

The nature of podcasts, which typically involve hosts speaking casually among themselves and to the listeners, creates an immediate intimacy with the audience. For advertisers, podcasts offer a built-in, loyal audience similar to the access an influencer can provide. Where a promoted social media post may appear in an Instagram user’s feed, podcast listeners have actively chosen to engage with the medium. That ownership leads to engaged communities that, in turn, are more likely to trust a host’s product recommendations. Advertisers seek to capitalize on that trust. For example, if a beloved podcast host uses a new toothbrush and speaks candidly about their experience with the product, perhaps a listener will, too.

Oral-care brand Quip directs podcast hosts to “talk about how Quip fits into their lives,” said head of marketing Shane Pittson. “I think the real and honest explanations of the wellness brands podcast hosts choose to endorse help people understand aspects of the product that are traditionally only understood through word of mouth.”

Pittson said oral care is an “unsexy and sparsely talked about part of everyone’s daily routine.” To combat that, the brand advertisers across paid social platforms. But the company has found success with podcasting, wherein the intimacy inherent in the medium makes hosts a natural fit to discuss their own wellness routines.

The timing is right to advertise on podcasts: Until 2017, podcast advertisers bought into individual shows. But spurred by industry growth, podcast network Panoply, home of shows by the Wall Street Journal and New York magazine, in addition to its own productions like “When Meghan Met Harry,” has introduced a service called Megaphone Targeted Marketplace, which allows advertisers to segment the audience and hyper-target their key demographics. The goal, said Matt Turck, chief revenue officer at podcast network Panoply, is for advertisers to work within their existing media-buying framework while engaging in an entirely new medium.

“It’s hard to fully quantify the impact and ROI of podcast advertising; since it’s an offline form of marketing, you don’t have access to the level of tracking that comes with digital forms of advertising,” said Craig Elbert, co-founder and CEO of vitamin brand Care/Of. “It gets even trickier to measure when we are also working with a podcast host on another one of their platforms, like Instagram.” Still, Care/Of continues to advertise on podcasts with the goal of reaching the right people with a message that’s curated just for them.

Sixty-seven million people, or roughly 20 percent of the population, listen to podcasts in the United States each month. It’s no surprise that podcasting has become a realm of interest for brands, who spent an estimated $220 million on podcast advertising in 2017.

In December 2017, Apple introduced Podcast Analytics, which offer hosts and podcast networks a wealth of data. Hosts can now learn how many people are listening through the entire segment, where listeners drop off and what they’re more likely to skip. So far, the data shows low levels of advertisements skipped. It helps that hosts are often directed to infuse ads with personal anecdotes told in the voice of the podcast, so skipping an ad can feel like missing out on part of the show. A survey by Panoply revealed that half of all listeners have bought a product advertised on a podcast.

“[Podcasts are] purposeful,” said Turck. “Unlike linear programming, the listener selects the programming they want to hear, when, where and on what device they want to hear it on. Often a familiar voice is discussing a product or service, so it’s inclusive and native.” Turck also points out that podcasts don’t suffer from the clutter of other mediums. An hour-long show may only have two or three 30-second advertisements.

Many wellness brands see podcasts as a crucial component of a well-rounded marketing mix. Hair-care brand Madison Reed advertises across social media channels, podcasts and radio, with the focus on various forms of paid social media promotions. Amy Errett, founder and CEO, voices radio ads herself. “It is not uncommon for Amy to speak to someone and for that person to say, ‘Hey, aren’t you the lady in those radio ads about hair color?’” said CMO Heidi Dorosin. Lola also advertises in online and offline mediums, from Facebook to search to mail.

“There’s no one marketing channel that truly dominates,” said Elbert of Care/Of. “But as someone who faithfully listens to my favorite podcasts on the very day they drop, I know how engaging they are. I would venture to say it’s also just fun for their audience to hear about their personal health routines.”

Apple alone is home to 525,000 active podcasts. The sheer number of interests and communities covered offers brands an opportunity to link up with their exact demographic. In iTunes’ health podcasts category, where wellness and beauty are typically situated, the top shows include Goop’s podcast, “Just Ask David” by beauty guru David Pollack, and “The Keto Diet Podcast.”

“When we started advertising on podcasts over two years ago, there were far fewer shows focusing on women,” said Friedman. “Especially in the past six to 12 months, we’ve seen a lot of new shows emerge that have helped to increase our scale in this channel.”