WPP Media Study Highlights Audio's Strong ROI Gains

RADIO ONLINE | Monday, November 10, 2025 | 2:44pm CT

Cumulus Media and Westwood One

WPP Media has released new findings that underscore the sales power of AM/FM radio and digital audio, revealing both short- and long-term return on investment (ROI) advantages over other media channels. This week's Cumulus Media | Westwood One Audio Active Group blog outlined the key findings from the study.

The study, titled High Gain Audio: Using Multiplatform Audio To Amplify Overall Media Campaign ROI, was conducted by Jane Christian, EVP Analytics for WPP Media, and is based on Profit Ability 2: The New Business Case for Advertising, one of the largest advertising effectiveness projects ever undertaken. The analysis drew on $2.2 billion in media spend across 142 brands, 14 sectors, and 10 media channels from 2021 to 2023.

According to the report, digital audio ROI outperformed the all-media average by +27% over a two-year period, ranking third among eleven media types. Broadcast radio followed closely, exceeding the average by +22% and ranking fourth. In the short term (one to thirteen weeks), digital audio tied for first in ROI -- 44% higher than the average -- while broadcast radio placed second with a +23% lift.

When advertisers reallocated 15% of their cross-platform budget to include 10% broadcast radio and 5% digital audio, total campaign ROI rose 5% in the short term. A larger allocation of 24% to audio lifted ROI by 8.2%, reinforcing audio's value as both a short-term sales driver and a long-term brand builder.

The study also explored what it calls the "paradox of ROI," noting that while higher ad spend increases overall profit, it can reduce ROI efficiency due to diminishing returns. The key takeaway: advertisers should aim for total profit growth rather than chasing the highest ROI percentage.

The findings continue to strengthen the case for AM/FM radio and digital audio as essential components of modern media strategies-proving that sound investment in sound pays off.

Read the full blog post here.