Audience research
Part of How to run radio advertising audience research for campaigns
How to identify a radio advertising target audience that buys
A method for defining and testing a radio advertising target audience, using RAJAR reach data, station splits and a scored shortlist you can defend.
What to take away
- Decide whether you are buying reach or a defined buying group: the two lead to different station lists and different spot lengths.
- Start from RAJAR's published reach and share figures, then filter for the regions you actually sell into.
- Score candidate audiences on size, fit, cost and measurability, and keep the evidence behind each score so the choice survives a client challenge.
- Test the shortlist on one station before committing a full schedule, and write the audience definition into the brief so the creative matches it.
Define the buying group before the station
A target audience is not a demographic. It is the group of people who can act on the advert within a reasonable period. A retailer running a two-week promotion wants people who pass a store. A software firm wants decision makers who can approve a licence.
Define the buying group
Who must hear this?
What must they do?
By when?
Write one sentence: who must hear this, what they must do, and by when. If it covers two separate actions, split it into two audiences and plan separate activity.
The wider radio advertising audience research guide for England shows how that audience work feeds a media plan.
Read the audience data properly
RAJAR publishes quarterly reach and share figures for UK radio, including digital and analogue splits. Check the published RAJAR quarterly listening figures to see how many people each station actually reaches before you accept a proposal.
Reach vs share vs dayparts
Reach
- What it measures
- Different people
- Why it matters
- Audience size
- Example
- Modest share, tight audience
Share
- What it measures
- Total listening
- Why it matters
- Station strength
- Example
- Bigger but broader slot
Dayparts
- What it measures
- Time of day
- Why it matters
- Who hears you
- Example
- Mid-morning beats breakfast
Reach is how many different people hear a station in a period. Share is how much of total listening that station holds. A station with modest share can still deliver a tight audience.
Dayparts matter too: breakfast and drive reach different people from late evening. If your product is bought during working hours, mid-morning may beat a bigger but broader slot.
Build a shortlist with a scoring rubric
Score every candidate audience out of five on each row. Weight the rows to reflect the client's objective, then compare totals and keep the note behind each score.
| Criterion | What good looks like | Weight |
|---|---|---|
| Size | Reach covers the sales area without heavy waste | 25% |
| Fit | Listening habits and station content match the buying group | 25% |
| Cost | Cost per thousand within the agreed ceiling | 20% |
| Measurability | Response can be tracked by code, number or landing page | 15% |
| Timing | Dayparts align with when the decision is made | 15% |
For example, a team paying £400 a month for spots on two stations might score high on cost and low on measurability. That is a signal to change the tracking before changing the buy.
Check the legal and competitive frame
Campaigns that collect responses by phone sit inside direct marketing rules. The ICO's guidance on direct marketing using live calls sets out consent and screening expectations, so read it before promising a call-handling route to a client.
Competition and consumer rules also shape what an advert can claim. The Digital Markets, Competition and Consumers Act 2024 is the current framework, and it matters when a script promises a price advantage.
Competitor activity belongs in the same file. Knowing which rivals already own a station or daypart stops you paying a premium for a crowded slot, and the method sits in radio advertising competitor research in England.
Test before you scale
Buy one station, one daypart and one creative route for a short flight. Set the response measure before the first spot airs, then compare cost per response rather than cost per spot.
If responses arrive but do not convert, the audience definition is wrong rather than the station. If nothing arrives, check the creative and the tracking before blaming the buy.
Record which daypart, message and offer worked. That record becomes the audience definition for the next flight.
Common questions
How large does a radio audience need to be?
Large enough to produce the response volume the client needs at an affordable cost per response. Work backwards from the sales target rather than picking a reach number first.
Can I use RAJAR figures for a single town?
RAJAR reports at published survey areas, which may be broader than one town. Check the smallest published area available before you promise town-level precision.
How often should the audience definition be reviewed?
At least once a quarter, when new listening figures land, and straight after any campaign that missed its response target.
Does the buying group have to match the station's typical listener?
No, but the further apart they are, the more you rely on creative and daypart selection to bridge the gap. Test that assumption on a small buy first.
