Study: Radio Steps In When Billboards Sell Out

RADIO ONLINE | Monday, May 11, 2026 | 2:41pm CT

Cumulus media and Westwood One

A new blog post from Cumulus Media | Westwood One's Audio Active Group highlights how one advertiser shifted a major outdoor advertising budget to AM/FM radio after key billboard inventory sold out, underscoring radio's continued strength in reaching in-car audiences.

According to the report by Chief Insights Officer Pierre Bouvard, the advertiser used data from Xperi's DTS AutoStage connected car platform to identify where AM/FM radio listening overlapped with desired billboard locations. The heatmap showed radio was reaching consumers in the same high-traffic areas-and beyond-prompting the shift in strategy.

The campaign also incorporated Quu in-dash visual ads, allowing the advertiser to replicate its billboard creative on vehicle dashboards. Research cited in the blog indicates 70% of agencies and advertisers are aware of these synced in-car visual ads and are willing to pay a premium of about 17% for the format.

Additional studies referenced in the report suggest that in-dash visuals can significantly improve campaign performance. A Quantilope study found strong gains across awareness, consideration and purchase intent, with 83% of consumers noticing dashboard visuals while listening to AM/FM radio.

The findings also point to a close relationship between outdoor and radio audiences. MRI-Simmons data shows consumers heavily exposed to billboards are 23% more likely to be heavy AM/FM radio listeners, with similar demographic profiles across both media.

In-car listening remains a key advantage for radio. Edison Research's "Share of Ear" study cited in the blog reports that AM/FM radio accounts for 83% of ad-supported audio listening in vehicles.

The blog also highlights the combined impact of radio and outdoor on digital campaigns. A UK study found that adding AM/FM radio to a media plan increased click-through rates by 29%, while the combination of radio and outdoor drove an 86% lift.

The case study illustrates how advertisers are increasingly turning to integrated media strategies, with radio serving as a flexible alternative when traditional out-of-home inventory is limited.

Read the entire blog post here.