The Download on Podcasts: New podcast guidelines from the IAB aim to standardize key terms

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In an effort to standardize technical terms for podcast producers, networks, and metrics analysts, the Interactive Advertising Bureau (IAB) came out of the Labor Day weekend with a release of IAB Podcast Ad Metrics Guidelines. (HERE is the PDF.)

“Podcast audiences represent a growing segment of effective marketable media but inherit challenges of legacy consumption platforms” — so begins the executive summary. this is an industry document with industry terminology, and here is the translation: Podcasting is an old thing enjoying new success.

iab podcast ad metrics guidelines title“This restricts the ability for advertisers to obtain the same data parity found in other digital mediums, limiting participation of some advertisers.” Translation: Advertisers can’t figure out who’s listening, so are afraid to buy in.

The Guidelines are not addressed to advertisers, but to producers and technical personnel who are trying to sell advertising. If there can be clarification of how podcast consumption works, and standardization of terms, some progress can be made in selling ads. This document does not attempt to solve the persistent audience analytics problems this column has discussed, though it does refer to the issue.

“This document offers the first step in an improved environment where buyers and sellers can start to use the same language with clearly defined meaning. As communication improves, producers will be able to scale their operations and invest in technology that brings tracking closer to the standards available in other media options,” the document concludes.

Three Key Definitions

We found the document especially effective when clarifying and defining the three modes that podcast listeners use. Podcasting is historically a download medium, founded as it was in the day when online listening was less practical and common than today. The difference between downloading and streaming podcasts is not as simple as you might think, and the IAB has clearly prioritized making it understandable.

The Guidelines distinguish three types of consumption at a technical level:

  • Downloading (for offline listening)
  • Online listening (but not exactly streaming)
  • Streaming (which happens from a unique type of server)

So, when a user “subscribes” to a podcast in the Apple Podcasts app, every episode is auto-downloaded to the local device, usually a phone. It can be heard at any time. When a user starts an instant listening action in the Podcasts app, it feels like streaming, but is actually downloading progressively as it plays, served from a download server just like a web page. When Pandora streams episodes of Serial, that is pure streaming from a streaming server, just like with Pandora music.

Podcast Player Market Share

The IAB solicited reports from podcast networks about which distribution apps pull their podcasts, by percentage. the idea was to get a rough distribution map. (PodcastOne, sponsor of this column, was one of the participating networks.)

Unsurprisingly, the Apple holds the biggest distribution share — between 53% and 65% of requests, most of that through the Podcasts app. That share generally corresponds with reports from other sources over the last 18 months or so. Browser listening happens between 6% and 14%, and Stitcher claims 2-7 percent. Everything else fills out the long tail of podcast distribution. There was variety from network to network in these numbers, except for the Apple Podcasts app, which soaks up the file requests equally for all participating networks.

How Ads Work

The Guidelines distinguish between integrated ads, which are baked into the file and cannot be moved out over time, and dynamically inserted ads, which are becoming more commonplace and are inserted at the moment the file is requested.

There’s much more about how ads should be regarded at the server level, and that portion the document goes into deeper waters technically. It suggests specifications of ad delivery that should be communicated to advertisers when explaining the marketing opportunity.

The 12-page document is a product of the IAB Tech Lab and the IAB Podcast Technical Working Group. Rockie Thomas (AdsWizz), Ilia Malkovitch (Google), and Amit Shetty (IAB) took the lead on document development.


Brad Hill