Last week Paragon held our final webinar on monetizing public radio’s unsold digital inventories. The three-part series, The New Sound of Sustaining Public Radio – A Webinar Series, concluded by hearing directly from the front lines of sellers and brokers who buy and sell public radio streams and podcasts. Panelists for Flipping the Script: What Programmatic Media Buyers Say About Public Radio included perspectives from multiple views of these transactions—

Rocks, Pebbles & Sand

A fundamental question was asked by a webinar attendee:

  • Why should public radio stations sell their digital inventory for the low CPMs offered?

Jen Oon of DAX US provided a great way to visualize the answer:

My recommendation is to visualize monetization of your inventory in this way. You have a glass jar. You have large rocks. You have pebbles, and you have sand. Normally, you want to put the large rocks in. The large rocks represent your local sales. Those are going to be your big sponsors. That’s your direct business where you’re going to ask for the highest CPM. You want to get as many of those as possible. You’re going to put those in the jar. The pebbles are going to be your mid-tier sponsors, where you probably can’t charge as much, but you still want to do direct deals with. Still do those. Programmatic is what is represented by the sand. That is the inventory that is really difficult and challenging to sell directly. You don’t have the manpower or the time. It may be inventory, right, that on its own is tough to sell. But there’s still pieces of inventory in there that you can monetize. That’s where programmatic buys come in, and you have full control over it. And again, you are in full control. You’re in control of how much is transparent in that inventory. Do you want your station to show up in there or not? You can control that. You can control the CPM. You can control exactly what type of advertisers are in there. My recommendation is to use that visual as a guideline. Bucket your inventory according to what you think it’s valued at and then sell it accordingly.

The panelists provided keys to an effective programmatic buying and selling process—

  1. Audience Value & Demand Growth: Public media listeners are highly educated, affluent decision-makers, and by and large, programmatic buyers listen to and align closely with public radio’s mission. Programmatic audio offers digital-first buyers an accessible, low-friction entry point to test and scale campaigns, with adoption expanding from 25–30% toward CTV-level penetration.
  2. Brand Safety vs. Brand Suitability: Brand safety is binary (e.g., blocking illegal or extremist content), whereas brand suitability is contextual and relative to brand risk profiles. Granular tools prevent the over-blocking of hard news and sensitive social topics core to public media’s mission.
  3. Episode-Level Transparency & Reporting Feedback: Audio programmatic bid streams deliver over 90% episode-level transparency, allowing buyers to validate performance metrics before transitioning into larger, direct publisher relationships.
  4. Publisher Control & Yield Optimization: Programmatic acts as incremental revenue (“sand”) to fill unsold or niche inventory without cannibalizing direct local sponsorship (“rocks”). Stations retain complete control over pricing floor CPMs, category exclusions, and advertiser blocklists.
  5. Multi-Layered Ad Quality Protections: Maintaining public media tone requires dual human and technological verification. Complementary publisher-side AI tools (e.g., SoundStack Ad Control) transcribe audio and parse concepts to catch miscategorized ads before broadcast.
  6. Listener Acceptance & Trust: Public media’s trusted “halo effect” delivers superior ad resonance and purchase intent. Listener pushback against programmatic formats remains minimal when strict audio quality, volume normalization, and contextual standards are enforced.

With sustainability now front and center across public media, Paragon started this conversation six months ago to raise awareness and understand the intricacies of digital monetization for public radio stations. While the first two webinars focused on the station perspective, the final webinar in our series exhibited the strong attraction that public radio holds among media buyers. My hope is that the stations can now make the best decisions on if and how to proceed with selling unsold digital inventory. Happy selling!

More about Mike.