How to Write a Radio Ad: The Craft Rules That Decide Whether Anyone Hears It

A thirty-second radio ad holds about seventy-five words at a pace a human being can comfortably follow, and most of the scripts that reach a production house carry closer to a hundred and forty. That arithmetic problem causes more bad radio than any other failure of craft, because a writer who will not cut is quietly asking the voice talent to solve it, and the only tool available in the booth is speed. Nielsen has reported for years that broadcast radio still reaches the large majority of American adults every week, and Edison Research has tracked online audio listening to a comparable share of people twelve and over through its annual Infinite Dial study. The audience is there. The page is where the spot usually dies.

Seventy-Five Words and a Stopwatch

Start with the budget that cannot be argued with. A fifteen-second spot runs to roughly thirty-five or forty words. A thirty holds seventy to eighty. A sixty holds a hundred and fifty to a hundred and sixty. Those figures assume a read at the speed of ordinary speech, which is the speed that sounds like a person rather than a disclaimer, and they assume the script does nothing else.

Everything else steals from the same account. A sound effect costs a second. A beat of silence before a punchline costs a second and is almost always worth it. A phone number read at a speed anyone could write down costs three to four seconds, which on a thirty is more than ten percent of the spot. A music bed that has to establish before the first line costs two. Write a hundred and ten words for a thirty and one of two things happens: the read turns into an auctioneer impression, or the producer cuts your copy for you and picks the wrong thirty words to lose.

The practical method is to write long, then cut to the count before anyone else reads it. Our walkthrough of the seven steps from idea to air covers what happens after the script is locked, and the copy stage is the one place where the cost of a change is zero.

What Gets Cut First

One spot carries one idea. Not one product and a reminder about the other location and the new hours and the anniversary sale. The reason is not aesthetic. A listener in a car is doing something else with most of their attention, and the memory that survives the next traffic light is a single hook attached to a single name. Two ideas in thirty seconds produce no ideas at thirty-one.

Business owners resist this harder than any other rule, and the resistance is reasonable, because they are paying for the airtime and they have six things to say. The answer is not to compress six into one. It is to write three spots that each carry two and rotate them, which costs far less than most people assume once volume pricing enters the conversation, and which gives the schedule variety the same budget would not otherwise buy. Our note on how volume pricing works lays out the arithmetic.

When a client insists on the kitchen sink, the test to put to them is simple and uncomfortable: name the one sentence you want a stranger to repeat to a spouse tomorrow. Whatever they say is the spot. The rest is the website.

The First Three Seconds Belong to Someone Else

Nothing in radio is owed attention. The spot arrives in the middle of a song, a traffic report or a podcast the listener chose on purpose, and the first three seconds compete against a steering-wheel button. Openings that lose immediately are the ones every listener has heard a thousand times: a rhetorical question about being tired of something, the phrase attention homeowners, a stack of adjectives in front of a company name, or a swell of library music under an announcer clearing his throat.

Openings that hold start in the middle of something already happening. A conversation already underway. A sound that does not belong. A flat statement with a number in it. The craft principle underneath is that the listener has to work out what is going on, and the half second of work is the attention. Comedy does this better than any other register, which is the argument behind our funny radio ad production work and the reason the funniest spots in any market tend to be the ones people can still quote a year later.

Saying the Name Without Begging

The station copywriting convention, taught the same way for decades, is three mentions of the advertiser inside thirty seconds. Treated literally it produces the hostage-video read, where a cheerful announcer says the name three times in a row at the end because nobody found a place for it earlier.

Place the first mention inside the action rather than on top of it. A character says it. A sign gets read aloud. Somebody is corrected about it. The second lands in the announcer's line with the offer attached, and the third is the tag, which is the only one that is allowed to be bare. The town name counts for almost as much as the business name in local radio, because the listener's first silent question about any advertiser is whether it is near enough to bother with.

Addresses are a trap. Nobody writes down a street number while merging. Give a cross street, a landmark or a town and send the rest of the work to a search bar, where it costs the listener nothing.

THE LIST, Thirty Seconds in Sellersville

Here is an original :30 built on everything above, written for a fictional hardware store, with the performance notes in brackets.

“THE LIST”, :30, two voices plus announcer, fictional client.

SFX: car interior, turn signal ticking.
WOMAN [on speakerphone, reading]: Gutter guards. A thing for the thing on the door.
MAN: The hinge.
WOMAN: The hinge. And the deck stain. The gray one, not the gray one you bought last time.
MAN: Those are different grays.
WOMAN: They are completely different grays.
MAN [already turning]: Kulp's has both.
ANNOUNCER [warm, unhurried]: Kulp Brothers Hardware, Main Street in Sellersville. Open seven days, and somebody in there knows which gray.
WOMAN: Also a mousetrap. The humane kind.
MAN: For the mouse or for me?
SFX: turn signal stops.
ANNOUNCER: Kulp Brothers. Sellersville.

Seventy-six spoken words. One idea, which is that the store has a person who knows the answer. The name lands three times without a single bare repetition at the end, the town lands twice, and there is no address, no phone number and no web address, because every one of those would have cost a joke. The last line of dialogue is a laugh the announcer talks over, which is deliberate: the listener finishes the thought themselves and remembers it as their own. More worked examples sit in our collection of radio ad scripts that convert.

The Test That Costs Nothing

Read the script out loud, standing up, with a stopwatch running. The tongue finds every problem the eye forgives: the consonant cluster that trips, the clause that needs a breath nobody has, the joke that reads funnier than it sounds. If it runs long standing in a quiet room, it will run long in a booth, because studio reads are usually slower than kitchen reads.

Then read it to one person who knows nothing about the business and ask them two questions a minute later. What was it for, and what was it called. If either answer is missing, the fault is in the copy and no amount of talent or music will cover it.

Six Things That Survive Into the Studio

These show up in finished, paid-for spots, which is how you know they survive every review the client ran. Spelling out a web address letter by letter, which eats four seconds to deliver what one search would. Two phone numbers. The phrase conveniently located, which has never persuaded anyone of anything. A list of three adjectives in front of the company name, which the listener hears as noise. A joke that has nothing to do with the product, which gets remembered while the advertiser does not. And invented urgency, the sale that ends Sunday every Sunday, which teaches a listener to discount everything else in the spot.

The common thread is that each one is a decision made to feel safe. Radio punishes safe harder than it punishes almost anything else, because a spot nobody notices costs the same as a spot everybody repeats.

Where That Leaves the Page

Write to the word count before anything else. Carry one idea. Open inside something already happening. Put the name in the action and the town in the tag. Read it out loud with a watch, then read it to somebody who owes you nothing. A script that survives all five is already better than most of what runs in any market on any given morning, and the production that follows becomes a question of casting and mixing rather than rescue.