“I don’t think podcasts require explanation anymore.” That is the assessment of Giles Martin, Executive VP of Client Strategy at the performance marketing agency Oxford Road. He said that his direct response clients are today looking for “all shapes and sizes” of podcasts. “There are lots of opportunities to be found,” he told the Podcast Movement conference last week in Orlando.

Sarah van Mosel, CRO at Stitcher, said the same can be said for the big brand advertisers. “Because of the engagement on podcast the brand community has found it and said there’s something going on here,” she said. “Also people in the ad community tend to be creative people and they are listening to podcasts so they themselves felt this heat around podcasting and wanted to figure out ways to get in there.”

As a result, the Interactive Advertising Bureau expects U.S. podcast revenue to reach $678.7 million this year. That would be a 42% increase over what advertisers spent on the medium last year when $479.1 million in revenue was logged. The IAB/PwC Podcast Advertising Revenue Study expects the pace of growth to remain strong with podcast ad market revenue forecast to surpass $1 billion by 2021.

“We are at a time where we have this robust base of performance-based direct response advertisers. And we have this growing base of brand advertisers coming in,” said van Mosel. “We’re no longer at time when you have to explain what a podcast is and how does it work. We’re now at a time where instead of ‘what is it?’ it is ‘how do I get in there?’”

One of the hurdles for brand marketers has been a lack of measurement. And while downloads remains the biggest metric used by podcasters to sell the medium, ad buyers have other data to justify using the medium. That includes a growing body of attribution data from Nielsen, among other third-party vendors. The continued use of podcasting by direct response marketers is also a loud and clear message to brand managers that podcast advertising sells products.

A Lot Of Vetting Required

But like listeners, sorting through more than 700,000 podcasts presents a challenge. Ryan Rose, Director of Sales at DAX, said it requires “a lot of vetting” to match a marketer with the right show. He said some advertisers are using the same technique that listeners rely on, such as word of mouth discovery. For a podcast looking to stand out, even if it doesn’t have big download numbers, a good option may be to accentuate its reach in a niche audience that could be highly engaged or one that’s heavily male or female, Rose said. “Downloads don’t matter so much, but that’s when it helps to be in a network where you can group with others,” he said. Rose added that it’s important for a podcaster to know what they’re selling before they even pound the pavement looking for ad dollars. “Know what your podcast is about and where it stands in the ecosystems. If you don’t know what your podcast is about and who your audience is, it’s not best to look for advertisers at that point,” he advised.

For his direct response clients, Martin acknowledged that a show with fewer than 5,000 downloads “starts to get pretty small and it’s a harder sell.” But he told podcasters that when they can include other components, such as a large social media reach, live reads and endorsements, some DR clients take notice and may be willing to give a podcast a try – even though download figures appear small. “That will improve the likelihood that we’ll succeed,” said Martin. He also suggested content plays a factor, such as a sneaker brand that would want to connect with a podcast all about sneakers. “We’re always looking for the perfect show for the client. If we find it, we’re very likely to give it a try no matter how big the sale. So there’s always an opportunity,” said Martin.