• by Joe Mandese , 6 hours ago

One of the greatest epiphanies for the multimodal nature of modern ad-supported media hit me a few years ago when Brian Wieser was still at GroupM -- and GroupM was still called GroupM -- and he and Kate Scott-Dawkins posted one of their "This Week, Next Week" podcasts (embedded below) discussing how much the "line items" they used in their bottoms-up approach to calculating the advertising marketplace had become fungible. Specifically, they discussed how a medium known for one modality -- say video -- could also be categorized as another, say audio.

The example they gave was YouTube, which we all know is the biggest video platform in the world, but according to Wieser, it had also become the biggest audio platform in the world. At least in terms of audio licensing, if not in advertising sales.

I was thinking about that when Google announced an advertising sales representation agreement Wednesday making SiriusXM Media the exclusive audio advertising rep for YouTube.

So I asked SiriusXM Media's press contacts if they could put some dimensions around the scale of the deal from an ad sales point-of-view. They declined.

And since this trade reporter's nature abhors a vacuum, I asked "someone" at Google -- Gemini AI -- to help me guesstimate it, based on the best publicly available data from its publicly-traded parent, as well as other public industry sources.

"While YouTube is the giant of video, it is a 'challenger' in the pure audio space compared to Spotify or iHeartRadio," Gemini replied, noting that much of YouTube audio content is actually "background listening," albeit "massive."

Utilizing Google's full-year 2025 reported data for YouTube gross advertising revenue ($40.4 billion) and applying industry audio share "norms" from the Interactive Advertising Bureau and other public sources, Gemini estimates audio's share of total YouTube advertising buys is about 3.3%, or about $1.4 billion for that year.

While that's not exactly chopped liver, it is a marginal share of the $40 billion-plus audio advertising marketplace.

So it makes sense that Google would seek to outsource it to a dedicated audio sales organization like SiriusXM Media, which also reps its own audio media inventory -- including the ad-supported Pandora streaming service, as well as an expansive podcast network -- and other third-party audio inventory from companies like SoundCloud and AudioMack.