Before you trust a podcast audience number, read the research rules

What to take away

Why reach figures mislead first

Reach is quoted in almost every pitch and answers the least useful question. A show can reach a large audience and still fail to move the product you sell.

When a team starts with reach, later decisions bend to protect it. Targeting loosens. Creative broadens. The campaign ends up judged on a metric that was never tied to the commercial goal.

That does not make reach worthless. It makes it a constraint rather than a brief. You need to know an audience exists before you spend on creative, and reach settles that quickly.

The usual sequence runs the wrong way round: deck, shortlist, then a scramble for evidence that the shortlist was right. That order makes research decorative.

Write the question first and you drop a show or two before the pitch, which is cheaper. Cost per thousand is easy to compare and easy to argue about, so teams default to it. Cost per outcome is harder to compute and far more useful.

The question before the number

Write one sentence naming the decision the research must support. For example: "Does a £12,000 test across three shows justify a repeat booking next quarter?" That sentence sets the population, the window and the precision you need.

Now name the population. Adults in England who listen to podcasts weekly are not the same group as adults in England who bought in your category in the past year. Vendors quote the wider one unless you ask.

Set the tolerance next. Choosing between two shows needs a tight band. Setting a budget line does not. Precision costs money, so buy only what the decision needs.

A brief that asks to "understand the audience" produces a study that answers nothing in particular. A brief that names one decision and one number produces something you can act on. Keep it to a single page.

Public data you can use

Start with what is already published and free. The ONS home internet and social media usage release covers digital access and usage patterns that underpin online audio consumption, and it is refreshed on a regular cycle.

RAJAR publishes quarterly listening data covering UK radio and audio reach and hours. It is not a podcast-only measure, but it gives a defensible denominator for audio behaviour when a vendor offers you a share figure.

Neither source tells you whether your buyer listens to a particular show. Treat both as the floor of your evidence, not the ceiling.

Read the notes before the headline. A percentage that excludes a group, or covers a different nation, will not survive a planning meeting. Note the fieldwork dates beside every figure you copy into a deck.

Build a one-page baseline sheet you reuse. Put the ONS access figure, the RAJAR reach figure and the fieldwork date for each on it. A new vendor number either fits that sheet or needs explaining.

Commissioning your own study

Commissioning is a specification exercise, not a shopping exercise. Write the brief, ask three suppliers to quote against it, and compare like for like. If a supplier proposes a different design, ask what it answers that yours did not.

Use established methods rather than invented ones. Ipsos publishes its approach to audience and media research, which is a sensible reference when you judge whether a proposed method is standard practice.

Keep the questionnaire short. Every extra question adds cost and fatigue, and fatigue shows up as straight-lining. Ten good questions beat forty careless ones.

Pilot the questionnaire on five people before fieldwork starts. Two of them will misread a question you thought was obvious, and fixing that costs nothing at that stage.

Budget for analysis, not just fieldwork. A cheap study with no crosstabs tells you less than free published data. If a quote looks low, ask what happens after the data is collected.

For a repeatable structure for your own fieldwork, the podcast advertising survey tools in England page covers question design and panel choices in more detail.

Interviews and personas

Surveys tell you what is true across a population. Interviews tell you why it is true. Run the interviews after the survey, so you can probe the anomalies the numbers threw up.

Recruit for behaviour, not opinion. Someone who bought in your category in the past six months has more to say than someone who says they would consider it. Behaviour is expensive to fake.

The podcast advertising customer interviews in England guide sets out recruitment and moderation, including the question patterns that lead a participant towards the answer you wanted.

Six to eight sessions is usually enough to hear themes repeat. When two sessions in a row produce nothing new, stop and write up. More interviews at that point add cost, not insight, because the marginal session repeats the fourth one.

Analysis is where teams cut corners. Tag the transcript against the decision in your brief, not against a generic code frame. Anything that does not touch that decision goes in an appendix.

Keep the recording and the consent record together. Store them where the media team can reach them. If a quote later appears in a pitch deck, you should be able to show the date, the question and the context it came from.

Transcripts alone change no decisions. The podcast advertising buyer personas in England article shows how to compress them into one-page personas carrying triggers, objections and the shows those people actually listen to.

Defining and sizing the audience

Once you hold data, define the audience in terms a buyer can act on. Channel, daypart, device and category interest all narrow a buy. "Podcast listeners aged 25 to 54" does not.

Size the audience for England if the campaign runs only in England. A UK-wide figure overstates your reach and understates your cost per head. State which nation a number covers every time you write it down.

Write the definition in the same words every time. If the brief, the screener and the media plan describe three slightly different groups, the results will not line up.

Agree the rounding rule with the buyer. Two teams can produce different audience sizes from the same data simply by rounding and de-duplicating differently.

Segments that cannot be bought are not segments. If no show or network can deliver the group you describe, change the definition before you change the plan.

The podcast advertising target audience in England article walks through sizing and segmentation, and it shows how to test a vendor's claimed reach against published audio data.

Claims, compliance and evidence

Any audience claim that appears in advertising falls under the advertising codes. The ASA and CAP publish research on advertising effects and compliance, which is useful when you decide how strongly you can state an effectiveness claim.

Keep an evidence file. If a claim is challenged, you will need the study, the questionnaire, the sample source and the fieldwork dates. A slide deck is not an evidence file.

Be careful with comparative claims. "Better than" needs a defined comparator and a defensible measure. "More likely to be remembered" needs a memory test, not a preference question.

Write the claim you intend to make before the study runs. If the design cannot support that sentence, change the sentence or change the design. Doing neither is how complaints start.

Date every claim you put in writing. One that was supportable on last year's evidence may not be supportable now, and the file should show which version you relied on.

Buying media with the research

Hand the buyer a one-page brief: audience definition, the metric that matters, the tolerance and the sources used. Buyers who receive a clear brief come back with better inventory options.

Agency-side planning practice is documented openly, and the IPA knowledge centre is a sensible reference for how planners build and defend a media plan. Use it when you argue for a test budget.

Set the test up so it can fail. If the research says the audience is there, the test should be able to show that it is not, or it proves nothing.

Keep the research file open through the campaign. If a show underperforms against the promise, the file is what you use to renegotiate the next booking rather than drop the channel.

Plan the read-out before you book the inventory. Agree who will judge the result, on which metric, and at what point you stop. The England market guide for 2027 covers how the buy side is likely to shift as inventory grows.

Scoring rubric

Use this to score any study, bought or internal. Score each row from 0 to 4. A total under 14 means the study should not carry a budget on its own.

Score the study before the pitch meeting, not after. Scores written in the room drift towards the person presenting.

Rows carry different weight. Decision fit and population matter more than method and sample when you are testing a small budget. Weight the rows in your own sheet if you need one number.

Reading a vendor deck

Look for the fieldwork dates first. A study from three years ago describes a different market, particularly in a category moving as quickly as podcasting.

Then look for the sample source. A panel that rewards completion attracts different people from a listener list. Neither is wrong, but they answer different questions, and the deck should say which was used.

Then look for the base size behind each chart. A 40% figure on a base of 25 is not a finding. Ask for the base and the confidence interval before you quote the number internally.

Check whether the deck reports listening or delivery. Downloads measure delivery. If the deck calls downloads listeners, every later figure inherits the error.

Ask for the raw question wording. Small changes in a screener can move an incidence figure by several points, and the wording is usually available on request.

Common questions

What is podcast advertising audience research?

It is the evidence you gather about who listens, what they do next and how many of them there are, used to decide where a podcast sponsorship goes. It covers published data, bought studies and your own surveys or interviews. The output should be a decision, not a report.

How much should a small team spend on it?

For example, a team testing three shows on a £12,000 media budget might put £1,500 to £3,000 into a short survey and six interviews. Spend enough to reduce the risk in the media budget and no more. If the media budget is small, use free published data and run interviews yourself.

Can I rely on platform download figures?

No. Downloads measure delivery, not listening, and the counting rules differ between platforms. Use them as a delivery check against the insertion order. For audience claims, use research with a stated method and a stated base.

How often should the research be refreshed?

Refresh the published baseline annually, and refresh your own study whenever the product, the price or the target group changes. Treat a study older than 18 months as background rather than evidence.