Persuasion is how an offer turns somebody arriving into somebody buying, and one test sorts every tactic you could use to get there. If your tactic relies on the customer not knowing about it, it is manipulation. If it still works after you have explained exactly what you are doing and why, it is persuasion, and understanding it should not leave anybody feeling deceived.
I don't really want this to be ethical, I just want it to be rational. The moral case for honesty in marketing can be left to one side, because the rational case is enough on its own: a tactic that depends on the customer staying in the dark works for as long as they stay there, and a tactic that survives being explained has nothing to lose on the day they find out.
Why the test is rational
Any movement away from the truth eventually forces the customer to justify your choice of words to themselves as ignorant, incompetent, inadvertently selfish or malicious. Those are the four explanations on offer once a customer notices the gap between what you said and what happened, and none of them is a position you can sell from afterwards.
The argument is about profit, not virtue. A business that persuades with things that aren't true fills its pipeline with customers who were promised something else, and good marketing is supposed to make the business better at making a profit, rather than scaling revenue for smaller and smaller gains in profit from more and more spend.
The test fits into one question you can answer in a few seconds. Would this still work if the customer could see the mechanism? If yes, carry on. If no, you are borrowing against somebody who has not been told.
Conviction does not pass the test just because it is sincere. When I was doing street ministry I went up to famous New Zealand All Blacks and offered to pray for them. I was certain, and certainty pressed on somebody else is pressure, not evidence: it gives the other person nothing to check, which is the same gap a hidden tactic leaves.
Six heuristics, each with two forms
The six usual heuristics are not mine. Robert Cialdini set them out in his 1984 book Influence: reciprocity, commitment and consistency, social proof, liking, authority and scarcity, with a seventh, unity, added in a later edition. Every one of them has a form that keeps working after it is explained and a form that only works while it is hidden, and the test is what tells them apart.
Authority. People trust expertise, and the form that holds up is capability somebody can check: real qualifications, real work and real results, described plainly. The manipulative form is Authority Theatre, which looks like faked credentials, bought links and "As Seen On" logos for appearances nobody saw. It works until someone checks, and shortcuts like these get a shorter shelf life with every algorithm update.
Social proof. People follow what other people do, so reviews and testimonials move decisions, which is exactly why they get manufactured. A 2019 study from Princeton researchers, Dark Patterns at Scale, crawled around 53,000 product pages across roughly 11,000 shopping websites and catalogued activity messages and testimonials of uncertain origin among the tricks it found. Real customers describing what they actually got, in their own words, is the form that survives somebody looking closely.
Reciprocity. Giving something useful first creates a pull to give something back, and the pull only holds if the gift is real and has no hook in it. A download that wants an email address before it gives anything is a trade the reader never agreed to, and if your business makes assumptions about customers and acts on them, you reach out to them as an intervention. My own stance since 2022 has been content free and ungated, with no funnel to buy into, and services priced openly.
Commitment and consistency. People act in line with what they have already agreed to, so a small yes makes a larger one easier. The honest version is a chain of kept promises: it's very simple to build trust, make a statement, a promise, then deliver on it, then repeat. Each kept promise earns the right to ask for a slightly bigger commitment. A first step that promises more than the second step delivers turns the same heuristic against you.
Liking. People buy from people they like, and the temptation is to manufacture likeability with a personal brand. A personal brand is a reputation, not a decision. If you have $10,000 to spend on personal branding, most of it, something like $8,000, is better spent on becoming better at the work, because in a personal brand you are the product.
Scarcity. A limit creates urgency, and the urgency is only worth something when the limit is real. The same 2019 study found countdown timers on offers that were still valid after the timer ran out, and low-stock and high-demand messages that appeared on every product. A real limit has a reason behind it that you could explain to the customer, and a fake one has nothing behind it but the customer's attention.
Framing and the downside
The same fact can be presented more than one way, and choosing the clearer way is not deception. The line is crossed when the framing hides the part the customer would want to know, because that part turns up eventually, on the customer's timetable rather than yours.
The honest frame tells the customer the awkward parts upfront. The cost before the call, the limitation before the deposit, the timeline before anybody has to ask. Marketing without a real difference underneath it has nothing true to frame, so it defaults to hype, and hype is where most bad framing comes from. The offer covers building something worth describing honestly in the first place.
The frame most funnels reach for has three roles in it, a victim, a villain and a rescuer, and it can be told honestly or not. Every funnel needs a victim works through where the line falls.
Dark patterns
Dark patterns are design choices that only work while the user has not noticed them: costs that appear at checkout, items added to the basket without asking, subscriptions that are hard to cancel, and the false urgency and false scarcity above. The 2019 Princeton crawl counted 1,818 instances across 15 types, found 183 websites using patterns that were outright deceptive, and identified 22 third-party companies selling them to shops as a ready-made service.
Every one of them fails the test by design. A cancellation flow built to be hard only keeps the customers who have not yet worked out what it is doing. The traps covers the wider habits that pull money toward tactics like these and away from the two levers.
The test, applied to this site
Most practitioners in the industry have something to sell you, and I do too, a book. This site also carries affiliate links, and the disclosure comes first rather than in the small print. I want affiliate links from more than one tool in each category, so that there is no incentive for me to push one over another, and the tools page is where that is laid out.
The same test applies to me. If you know that a link pays me, and the recommendation still makes sense to you, it is persuasion. If it only works because you didn't know, it isn't.
Where persuasion sits
Persuasion works on the offer side of the equation, at the moment somebody who has found you decides whether to act. Underneath it sit the human drivers, which explain why one person responds to an offer and another walks past. Before any of it is scaled, validation puts the offer in front of real people and checks whether they pay.
Every persuasive act either builds trust or spends it, and the Trust Algorithm is the model that captures the result over time.
Use the six heuristics in their real forms, describe what you actually do, and keep every tactic you would be happy to explain to the customer it is aimed at.