What is podcast advertising, and how is it bought?
Advertising inside audio programming, and its distinctive property is that a large share of it is read by the host — which is why it performs differently from almost every other advertising format.
The formats:
Host-read, where the presenter delivers the message in their own words. This is the format that works, because it borrows the host's credibility and the parasocial relationship listeners have with them.
Announcer-read or produced spots, pre-recorded and inserted, which perform closer to ordinary radio advertising.
Branded content or sponsored series.
By position: pre-roll at the start, mid-roll within the episode — the most valuable, because listeners are committed — and post-roll at the end.
How it is inserted, which determines how it is bought:
Baked in, permanently part of the audio file. Lives forever in the back catalogue, which gives a long tail and cannot be changed or removed.
Dynamically inserted, stitched in at download time. Allows targeting by geography and device, changing campaigns, and replacing ads later — and it is now the dominant method.
How it is bought: directly with a show; through networks and sales houses representing many shows; via programmatic marketplaces; or through platform advertising systems.
The measurement problem, which is real. Downloads are not listens; listens are not attention. The industry standard counts a download meeting certain criteria, and skipping is invisible. Attribution therefore uses:
Promotional codes and vanity URLs, which undercount because many listeners search the brand name instead.
Pixel-based attribution, matching exposure to site visits.
Brand lift surveys.
Post-purchase surveys asking how people heard, which is crude and frequently the most honest signal available.
Why it works despite the measurement weakness: high attention, an engaged and frequently loyal audience, ad-avoidance being harder in audio, and the host's endorsement carrying weight that a banner cannot.
What makes a campaign fail: a script the host reads verbatim and awkwardly, a product they have obviously never used, and expecting immediate direct response from a brand-building medium.