How do podcast ads work?
Podcast ads are either read by the host, sometimes recorded once into the episode, or inserted dynamically when a listener downloads or streams the episode. Dynamic ad insertion lets publishers sell targeted, time-bound ads across a back catalogue. Ads are usually priced per thousand downloads (CPM) or per episode, and measured with download data, promo codes and attribution pixels.
Podcast advertising relies on dynamic ad insertion for scale: the hosting server stitches ads into the audio file at request time, targeted by location, device or show. Programmatic audio also covers streaming music services and digital radio.
Measurement is looser than on the web because a download does not prove a listen. The IAB's podcast measurement guidelines define valid downloads and filter bots and duplicate requests, which matters because download inflation is a known fraud risk in audio.