Last year, the IAB New Zealand Digital Audio Effectiveness Group released the Digital Audio Buyers Guide: a resource designed to help media planners and buyers better understand the role digital audio can play within the modern media mix. This year, they are expanding on that work through a series of articles exploring the evolving audio landscape in greater depth. This second article details how to drive more effectiveness with digital audio.
Digital audio can deliver strong ROI when used intentionally.
As a channel it tends to be under-credited in media plans,
That upside comes with a caveat. ROI performance for digital audio and podcasts has a wide range, from slightly below TV and terrestrial radio at the low end, to more than double at the high end. Where a campaign lands on that range depends on the fundamentals: sufficient reach within the channel, sustained investment over time, and creative quality. On that last point, Analytics Partners attributes 55 - 60% of audio effectiveness to creative quality, with the remaining 40 - 45% coming from media execution.
Indexed ROI Performance Range by Medium
Source: Analytics Partners
The strongest audio plans combine terrestrial and digital
New Zealand's smaller population means digital audio doesn't have the scale to stand alone the way it might in bigger markets. This is why an audio-agnostic approach (planning terrestrial and digital audio together, rather than as competing line items) tends to deliver the strongest total results.
Terrestrial radio does what it does well: it delivers reach and frequency at scale. Digital audio does something different: it delivers incremental audiences, sharper targeting, and a higher return per dollar on the inventory it owns. Neither replaces the other, they're solving different parts of the same brief.
The most effective audio strategy uses terrestrial as the foundation and digital as the multiplier, with the ROI data simply informing how the two are weighted against each other.
It works across the full marketing funnel. Not just awareness.
Source: Nielsen CMI Q1 24 - Q4 24 Jan 25 Fused (weekly).
Digital audio is frequently planned as a reach and awareness tool, then left out of consideration and action briefs altogether. That undersells what it's capable of.
At the awareness stage, digital audio's role is familiar: a growing, highly engaged audience, incremental reach alongside the rest of the media plan, and data-informed, on-target delivery. But its usefulness doesn't stop there. At the consideration stage, digital audio offers a highly personalised, one-to-one advertising experience, contextual relevance through content and topic alignment, and the trust listeners place in the voices they follow. At the action stage, it offers an addressable environment backed by data, with frictionless calls to action built into the digital inventory itself. A plan that puts digital audio in the awareness box only, and nowhere else, is applying half the tool. The same funnel logic used to justify social or video belongs equally to audio.
Audio primes the brain to be more receptive to the broader media mix
Neuro-insight research, in New Zealand and overseas, shows what happens to memory encoding when audio precedes other advertising. A 2021 study by The Radio Bureau found that, without priming, a TV ad produces relatively flat memory encoding across its 30 seconds. When the same ad is preceded by audio, measurable spikes appear at the key message moments, the product image, and the brand recall point.
Memory Encoding
Source: In One Ear, radio and memory encoding. The Radio Bureau _ Neuro-insight. 2021
The Radio Centre in the UK found a similar effect with social: reallocating a portion of social budget into audio increased paid social referrals by 13%, without adding to the overall spend. The audio exposure builds the memory structure and brand familiarity that make the downstream digital touchpoint work harder.
ROI Multiplier
Source: The Radio Centre Performance Multiplier research (includes radio + online audio)
Any plan running social, video, and likely others, without an audio component may be running those channels below their potential - the priming effect simply isn't there to support them.
Digital audio’s expansive content ecosystem is a hidden strength
Someone listening to a true crime podcast, a business news briefing, or a workout playlist is telling you something about their mindset and what they're open to at that moment. This context is a genuine audience signal.
Contextual targeting is highly effective: According to Analytics Partners genomes, up to 2.5x more effective than other targeting approaches across the media mix. This is part of what sets digital audio apart. The vast listening environment (genre, topic, content mood) provides so many contextual targeting scenarios, and a message placed in the right content environment arrives with relevance already built in.
With digital audio, context targeting also allows you to get around other targeting limitations. Limited data feedback between channels and podcast content management systems means available inventory narrows faster than targeting parameters allow, and delivery can suffer as a result.
While digital audio does offer a vast targeting toolkit spanning content alignment, listening context, and data signals, it tends to work best when context leads and data adds signal rather than restriction. Knowing where an audience is listening can be more useful than knowing precisely who they are.
Additional Resources:
For a deeper look at how to approach digital audio planning, buying, and measurement download the
IAB New Zealand Digital Audio Buyers Guide
Read the first article in this Digital Audio series here 'Digital Audio is Bigger Than Most Media Plans Reflect'
Thank you to the contributing members of the IAB New Zealand Digital Audio Working Group for this article:
Kate Grigg, Head of PMX New Zealand, Publicis Media Groupe | Chair IAB New Zealand Digital Effectiveness Council
Hannah Merritt, Strategy Director, PHD Aoteroa (Working Group Lead)