Good advertising copy: formulas, examples and how to test it

Good advertising copy states one clear benefit, speaks to a specific person, and ends with an action worth taking. In paid search it has to do that inside a 30-character headline. The gap between a weak line and a strong one routinely shows up as a difference in click-through rate, not a difference in taste.

The average consumer meets somewhere between 5,000 and 10,000 commercial messages a day. Almost all of them are ignored, and the ones that are not tend to share the same handful of properties.

This guide covers what separates copy that converts from copy that fills space, the three formulas worth knowing, how to write for the character limits of paid search, and why your A/B test results may be lying to you.

What is advertising copy?

Advertising copy is the text in an ad that persuades someone to take a specific action: buy, sign up, click or enquire. It is not about sounding clever. It is about matching a business goal to something the reader actually wants, in the space available.

What makes copy good?

Great copy takes many forms, from dry to funny, and the good versions all obey the same principles.

• Clarity. Say what you mean, immediately. If the reader has to work out what you sell, they have already gone.
• Relevance. Copy that converts feels written for one person. That requires knowing what they are actually trying to solve, not what you would like them to care about.
• A stated value. Features do not sell. What the feature does for the reader sells.
• Emotion. People decide on feeling and justify with facts. Copy that only presents facts is asking the reader to do the harder half of the work.
• A specific call to action. "Submit" and "Click here" waste your closer. "Get my free guide" tells the reader what they receive.

The size of the effect is easy to underestimate. Changing a call to action from "Learn more" to "Get my free guide" can double click-through rate on the same creative and the same audience.

What are the types of advertising copy?

• Direct response. Built for immediate action. "Join 10,000 professionals using our app. Free download this month."
• Brand storytelling. Built for long-term association. "We started with one belief: skincare should be honest and affordable."
• Social ad copy. Built to stop a scroll and earn a tap.
• Paid search copy. Built to match a query and win the click. "Affordable web design. Fast turnaround, free consultation."
• Video scripts. Built to hold attention in the first three seconds.

Writing for paid search, where the space runs out

Search ads are the hardest format because the constraint is absolute. You get 30 characters per headline and 90 per description, and the searcher has already told you exactly what they want by typing it.

What works inside that box:

• Put the query in the headline. Matching the searcher's own words is the single most reliable lift available, and it improves relevance scoring as well as click-through.
• Lead with the outcome, not the company. Nobody searches for your brand unless they already know it.
• Qualify in the ad. Stating a price, a minimum or a market filters out clicks you would pay for and never convert. A slightly lower click-through rate with a higher conversion rate is a better campaign.
• Write assets that work in any order. Responsive search ads assemble combinations you did not write, so every headline needs to stand alone.
• Match the landing page. The promise in the ad has to be the first thing on the page, in the same words.

The character limits and how to work inside them are covered in more detail in our guide to Google Ads headline character limits.

Three copywriting formulas that hold up

AIDA: attention, interest, desire, action

Open with a hook, build curiosity with a relatable problem, show the benefit or proof, then close with the action. Works for landing pages, longer ads and email campaigns.

PAS: problem, agitate, solution

Name the problem, make the reader feel its weight, then present the way out. Best for urgent pain points and social ads, and easy to overdo.

FAB: features, advantages, benefits

List what the product has, explain how that is better, then connect it to the reader's situation. Best for product and service pages where the buyer is comparing options.

Common mistakes

• Vagueness. "Best in class" says nothing. A number says something.
• Overclaiming. Exaggeration earns the click and loses the sale, and on regulated products it earns a disapproval.
• Ignoring the platform. Copy that works on Instagram fails on Google, because one interrupts and the other answers.
• Burying the action. If the reader has to guess the next step, there is no next step.
• Writing for the brief. Copy approved by a committee usually reads like it.

Testing your copy, and why the result may be wrong

A/B testing headlines, calls to action and tone is the only way to find out what works with your audience rather than in general. Track click-through rate, conversion rate and cost per real conversion, and give each variant enough volume to mean something.

Here is the part that is usually missed. An A/B test compares two variants using the traffic that arrived, and assumes that traffic was human and interested.

If a meaningful share of your clicks came from bots, competitors or click farms, the test is measuring something else. Invalid traffic does not distribute evenly across variants, because automated clicking follows position and timing rather than persuasion. The variant that "won" may simply be the one that was served during a burst of bot traffic.

The symptom is familiar: a variant with an excellent click-through rate and a conversion rate that collapses when you scale it. That is not creative fatigue, it is a measurement problem.

Before trusting a copy test, confirm the traffic behind it. Bot detection separates automated clicks from real ones, and click fraud protection keeps them out of the campaign so the next test starts from clean data.

Voice and consistency

Your tone should stay recognisable across channels, whether that is informal or precise. Consistency is what makes a returning visitor feel they are in the right place, and it costs nothing except the discipline to write a short style guide and use it.

Where AI helps and where it does not

Generative tools are useful for volume: forty headline variations to react to, first drafts of descriptions, rewrites at different lengths. They are poor at the thing that actually matters, which is knowing what your customer is worried about at the moment they search.

Treat AI output as raw material. The specific detail that makes copy land, a real price, a real timeframe, a real objection, still has to come from someone who knows the business.

Your copy is the only part of the ad most people read

Good advertising copy is specific, honest and written for one person with one problem. The formulas help you structure it and testing tells you whether you got it right.

Just make sure the data behind the test describes real people. Copy optimised against polluted traffic gets better at attracting the wrong audience, and it does it very efficiently.