Marketing claims: how to test one before you publish it
Quick answer
Test a claim with four questions: what it asserts as a plain statement, what the source is and whether you can produce it, whether that source is about the same thing, and whether it would still mean anything if a competitor said it. A claim that fails any of them is a liability, not copy.
Every marketing sentence is a claim, including the ones that do not look like ones. “Saves time”, “works for busy people”, “the simplest way to do this” are all assertions about the world, and each is capable of being false. The discipline below is about deciding which of them you can prove before you publish, rather than after somebody asks.
Three kinds of statement, only one of which is a claim
Opinion is attributed and personal: “we think this is the clearest interface in the category”. It is not a claim about fact, and it is generally acceptable when it is clearly opinion.
Puffery is vague praise no reasonable person reads literally, and most regimes tolerate it. The boundary is not fixed, and it moves toward prohibition as the statement becomes specific enough to be tested.
Claim is a specific assertion about a product, an outcome or a comparison. This is the category that needs evidence, and the usual failure is not inventing evidence but failing to notice that a sentence became specific.
The practical test: could a competitor, a regulator or a customer reasonably say “prove that”? If yes, it is a claim, whatever grammatical form it takes.
The adjective problem. Most accidental claims are adjectives that were chosen for rhythm. “Faster” is a claim; “faster, on the benchmark we publish below” is a claim you have already proved. The second is only slightly longer to write and removes the entire risk.
What a defensible evidence file contains
- The claim, written out. Not the page it appears on — the sentence itself, verbatim, including any qualification.
- The basis. A test, a survey, published research, a standard, or a calculation. Name which.
- How it was produced. Method, sample, dates, and who ran it. A result without a method is not evidence; it is an assertion in a larger font.
- The limits. What the evidence does not establish. A claim that has not been narrowed is usually wider than its proof.
- When it expires. A price comparison goes stale, a survey goes stale faster, and a claim about a competitor’s product may become false when they change it.
Choosing the weaker claim that you can prove
This is where most of the value sits. Teams tend to pick the strongest claim they can imagine and then look for support, which produces either an unsupported claim or an expensive study. Reversing the order is cheaper and safer: start from what you already have evidence for, and word the claim to fit it.
A weaker claim that is true converts better than a stronger one that a prospect doubts, because doubt is contagious and it spreads to the parts of the page that were not exaggerated. The strongest rhetorical claim you can defend is a business asset; the strongest one you cannot is a liability that occasionally converts.
Where the test applies before publishing
- Read the claim in isolation, without the page around it. Context does the work of qualification, and the claim will be read alone somewhere eventually.
- Ask what the reader would conclude if they believed it. If the conclusion is larger than the evidence supports, the wording needs to move, not the evidence.
- Ask what the strongest true version of the sentence is. Write that instead.
- Ask who would dispute it. If nobody could, it probably is not saying much; if a competitor could, they might.
Comparisons need the other side. A claim that your product is better than a named competitor’s needs evidence about that competitor’s product, which is harder to obtain than evidence about your own and which they may know better than you do. Comparisons stated against “typical” or “ordinary” alternatives avoid the problem and are usually weaker than they look.
Legislation differs, so name the regulator not the country
The core principle — a claim must be substantiated, and a misleading omission is as actionable as a misleading statement — is common across most consumer protection regimes. What differs is who decides and what happens.
In the United States the Federal Trade Commission administers the standard and requires substantiation for objective claims before they are made. In the European Union the Unfair Commercial Practices Directive sets the framework and national authorities enforce it. In the United Kingdom the Digital Markets, Competition and Consumers Act 2024 consolidates the consumer protection rules and gives the Competition and Markets Authority direct enforcement powers.
The useful habit is to write the jurisdiction into the evidence file rather than assuming the rules you know apply everywhere — for detail see advertising claims and substantiation.
What to do when a claim is already live
Fix it before anyone asks, and keep the record of the fix. A corrected claim with a dated note is a much better position than the same claim defended, because the defence is usually that the wording was not intended to be read literally — which is an admission that it was read that way.
Common questions
How do I test whether a marketing claim is safe?
Rewrite it as a plain statement, name the source and confirm you could attach it to an email, check the source is about the same product and population, then ask whether a competitor could say the same sentence. If any answer fails, rewrite the claim.
Are testimonials and reviews always acceptable?
Only when they are what the customer actually said. A review you wrote, bought, or edited into a different sentiment is a false claim in a customer's voice, which is worse than making the claim yourself.
Why are superlatives risky?
A superlative such as number one or the best is a claim about the whole market at a point in time. Unless you can name the basis and the date, a narrower true sentence is both safer and more persuasive to a careful buyer.