Audio Advertising ROI in 2026: What Radiocentre’s WPP Media Study Says About Shifting Budget

Updated September 30, 2026: Search and social advertising still dominate many performance-marketing plans, but a growing body of media-mix research is making a case for something less fashionable: audio.

Radiocentre’s High Gain Audio research, conducted by WPP Media, argues that broadcast radio and digital audio can deliver stronger profit return on investment than the average media channel and that reallocating some existing budget into audio may improve total campaign returns. The practical idea is not that brands should abandon paid search or social. It is that an over-concentrated digital mix may leave profitable reach on the table.

The strongest headline from the 2026 report is that total campaign short-term ROI was highest in the study when multiplatform audio reached roughly 25% of total media spend. At that point, the modeled uplift was about 9% versus a comparable mix with no audio. Radiocentre published the full findings in April 2026 and describes the work as a WPP Media analysis of advertising effectiveness. Read the Radiocentre summary of the 2026 report.

What the High Gain Audio study found

The research separates two broad forms of audio advertising:

• Broadcast radio — traditional commercial radio listening.
• Digital audio — podcasts, streaming audio and connected-device listening.

Radiocentre says the two formats work best as complements rather than substitutes. In its published findings, multiplatform audio produced a short-term profit ROI of about £2.50 for every pound spent and a full-term profit ROI of about £5.00. The organisation says these results were above the all-media averages in the dataset.

The High Gain Audio research page provides the methodology, charts and recommendations behind those figures.

Why shifting some search and social budget into audio is being discussed

Paid search and paid social are attractive because they are measurable, optimisable and easy to switch on or off. That convenience can also create a planning bias. Teams sometimes keep adding budget to channels because the dashboards are familiar, even after marginal returns begin to flatten.

That is the key concept behind the audio argument: marginal ROI. A channel can have good average performance but still deliver weaker returns on the next pound spent if it is already heavily funded. Another channel with lower current spend may have more room to scale efficiently.

Radiocentre’s analysis suggests that audio had meaningful marginal headroom in the campaigns studied. The report specifically identifies pure-play digital formats — including paid social, online display, online video and PPC — as possible sources of budget for a larger audio allocation.

Does the research mean brands should move 25% of every budget into audio?

No. That would be too literal an interpretation.

The 25% figure comes from the specific campaign data analysed in the study. It is a useful planning signal, not a universal rule. Media effectiveness varies by category, geography, creative quality, purchase cycle, audience, distribution, pricing and brand maturity.

A direct-to-consumer skincare brand with a short consideration window will not necessarily have the same ideal mix as a national bank, supermarket or automotive manufacturer.

The better takeaway is this: if a brand is highly concentrated in search and social, it may be worth testing whether a broader mix improves incremental reach and profit rather than assuming the next dollar belongs in the same channels.

Audio’s advantage: reach without the same screen competition

Digital advertising is crowded. On a phone screen, a brand may be competing with messages, short-form video, notifications, creators and dozens of other ads within a few minutes.

Audio operates differently. A radio spot, podcast integration or streaming-audio ad can reach people while they are driving, exercising, cooking or working — moments when visual inventory is either unavailable or less dominant.

That does not automatically make audio more persuasive. It does mean the medium can add reach that is not simply another impression inside the same visual ecosystem.

Why performance marketers should care about brand channels

One of the most persistent mistakes in digital marketing is treating “brand” and “performance” as separate worlds. Search looks like performance because the conversion path is easy to see. Radio or podcast advertising may look like brand because the path is less direct.

In reality, upper-funnel media can create demand that later appears in branded search, direct traffic, organic search or paid social retargeting. If attribution gives all the credit to the final click, the channel that created the demand may look weaker than it really was.

This is why media-mix modelling matters. It tries to estimate how multiple channels work together rather than assigning all value to the last measurable interaction.

For readers building broader measurement systems, BCC’s guide to free marketing analytics tools for teams covers practical platforms that can help organise campaign data before moving into more advanced modelling.

How audio can influence search performance

Audio and search are not necessarily competitors. They can reinforce each other.

A memorable radio or podcast message can create:

• more branded searches;
• higher direct traffic;
• greater familiarity when a paid-search ad appears later;
• better response to social ads because the brand is already recognised;
• more organic discovery after offline exposure.

That is why budget reallocation should be measured at the total campaign level rather than judging audio only on immediate clicks. Audio can be effective even when the final conversion happens elsewhere.

Broadcast radio and digital audio do different jobs

The report’s recommendation to use digital audio as a supplement rather than a replacement for broadcast radio is interesting because the two formats solve different planning problems.

Broadcast radio

Broadcast radio can deliver rapid mass reach, especially in local and commuting audiences. It is useful when a brand needs broad awareness within a defined geography or demographic.

Digital audio

Digital audio gives planners more granular targeting and can reach listeners through streaming services, podcasts and connected devices. It may be easier to align with behavioural or contextual audience segments.

A blended strategy can use radio for scale and digital audio for precision.

What marketers should test before moving budget

Rather than making one large budget shift, a disciplined test is more useful.

1. Establish a baseline. Record current revenue, branded search volume, direct traffic, paid-search efficiency and social conversion metrics.
2. Choose a meaningful test market or period. The test needs enough scale to detect change.
3. Move a controlled share of spend. Do not destroy the existing acquisition engine just to prove a theory.
4. Use distinctive creative. Audio needs memorable brand cues, a clear proposition and simple language.
5. Measure beyond clicks. Track search uplift, direct traffic, conversion rate and total profit.
6. Compare incrementality, not vanity metrics. Reach and impressions matter only if they change business outcomes.

Why creative quality matters more in audio

Audio has no visual safety net. A weak script cannot be rescued by beautiful product photography.

Good audio creative usually does a few things quickly:

• names the brand early enough to be remembered;
• uses a recognisable sonic cue, voice or music device;
• communicates one main benefit rather than five;
• sounds natural rather than like a brochure being read aloud;
• gives the listener a simple next step.

This is one reason audio performance can vary dramatically between campaigns even within the same category.

Where this fits in a modern marketing mix

The broader lesson is not “audio beats digital.” It is that channel performance depends on how channels interact.

Search is excellent at capturing existing intent. Social can create and harvest demand. Video can demonstrate. Audio can build familiarity and mental availability while people are away from screens. The most efficient plan may combine all of them rather than forcing one channel to do every job.

That idea also applies to ecommerce growth. Our D2C performance marketing strategy guide explains why profitable growth usually requires balancing acquisition costs, creative testing, retention and measurement instead of chasing one platform metric.

And for teams heavily dependent on Google, our Google Marketing in 2026 guide provides context on how search, Ads, Maps, analytics and AI-driven discovery now fit together.

A note on the study’s limitations

Radiocentre represents the UK commercial radio industry, so readers should remember that it has a clear interest in demonstrating the value of audio. The analysis was conducted by WPP Media, and the published report provides more detail than a simple promotional claim, but the findings should still be interpreted as evidence to test rather than a guarantee.

The deeper marginal-ROI analysis also uses a smaller subset of campaigns than the overall dataset. That makes the direction of the finding useful, while the exact “ideal” percentage should not be copied into every media plan without validation.

What the study changes for 2026 media planning

For years, many marketing teams have defaulted toward channels that are easiest to attribute. The High Gain Audio findings are another reminder that what is easiest to measure is not always what creates the most incremental profit.

The most practical next step is not to cut search or social blindly. It is to ask whether those channels are already past their most efficient point and whether a controlled audio test can improve the performance of the whole mix.

Frequently asked questions

What is audio advertising?

Audio advertising includes commercial radio, streaming-audio ads, podcast ads and other paid messages delivered through audio environments.

What did the High Gain Audio study find?

Radiocentre says the WPP Media analysis found above-average profit ROI for broadcast and digital audio and modeled higher total campaign ROI when audio received a larger share of media spend.

Should brands move 25% of their budget into audio?

Not automatically. The 25% figure was the strongest point in the study’s specific dataset. Brands should test their own audience, economics and creative before making a large allocation change.

Can audio help paid search?

Potentially. Audio can increase brand awareness and branded-search demand, which may improve later performance in search and other digital channels.

Is digital audio better than radio?

The study argues that they are complementary. Broadcast radio can provide scale, while digital audio can add targeting and additional listening environments.

Sources

• Radiocentre — 2026 High Gain Audio report summary
• Radiocentre — High Gain Audio research and methodology

Featured image: representative audio-studio photograph from Unsplash.