Here is a question that should make every marketer slightly uncomfortable: when was the last time you told a potential client what you are bad at?
Not in a humble-brag, “our only weakness is that we care too much” sort of way. Properly bad. The kind of honest admission that makes your pitch deck feel naked.
On a recent episode of Embracing Marketing Mistakes, Will and I sat down with Phill Agnew, host of the Nudge podcast and one of the sharpest behavioural science minds in UK marketing, to talk about something that goes against every instinct we have as communicators: why the most persuasive brands in the world go out of their way to highlight their weaknesses.
The answer sits at the intersection of two powerful concepts: the pratfall effect and two-sided arguments. And once you understand them, you will never look at a Guinness advert the same way again.
The Pratfall Effect: Why Being a Bit Rubbish Makes You More Likeable
The pratfall effect is one of those behavioural science concepts that sounds too good to be true. The basic idea, first demonstrated by psychologist Elliot Aronson in the 1960s, is that competent people (and by extension, brands) become more likeable when they show a small flaw.
Aronson’s original experiment had participants listen to recordings of quiz contestants. The contestant who got nearly every answer right and then spilled coffee on himself was rated the most likeable. Not the perfect one. The one who tripped up.
As Phill explained on the podcast, this transfers directly to marketing. Think about Guinness. For decades they have run one of the most successful advertising lines in history: “Good things come to those who wait.” That is not a boast. That is Guinness openly admitting that their product takes ages to pour. A 119.5-second wait, to be precise. Most brands would hide that. Guinness turned it into their entire identity.
I actually think it is also because Guinness is a lovely pint, but I do love the thinking here. They took the one thing a punter might complain about at the bar and made it the reason you order.
Two-Sided Arguments: The Art of Telling People Why They Might Not Want You
The pratfall effect is one piece of a bigger puzzle. The broader technique is what researchers call two-sided arguments, and it is arguably the most underused persuasion tool in marketing today.
A two-sided argument is exactly what it sounds like: instead of only presenting the positives (which is what 99% of marketing does), you acknowledge a genuine weakness alongside your strengths. The research on this is staggering. Studies show that two-sided messages are significantly more persuasive than one-sided ones, particularly with educated and sceptical audiences.
That is totally counterintuitive, right? You would think that admitting a flaw would put people off. But actually the opposite happens. When you acknowledge a weakness, it makes everything else you say more credible. Your audience thinks, “Well, if they are honest about that, they are probably honest about the good stuff too.”
Phill walked us through some brilliant examples. Volkswagen’s classic “Think Small” campaign leaned into the fact that the Beetle was tiny and ugly at a time when American cars were huge chrome barges. Liquid Death sells water in cans that look like they should contain industrial solvent, with a name that sounds like a heavy metal band. They are not hiding from the absurdity. They are leading with it.
The England Football Test (Or: How to Spot a Two-Sided Argument in the Wild)
I find the easiest way to think about two-sided arguments is with football. If someone tells you England are going to win the World Cup because Bellingham is brilliant, Kane is lethal and the midfield is the best in Europe, you nod politely and think they are deluded.
But if someone says, “Look, our defence is a bit of a worry and Tuchel is still working out his best eleven, but Bellingham is on another level and if Kane stays fit we have got enough to beat anyone on our day,” you are suddenly thinking, “Actually, fair point.” Same conclusion. Completely different credibility. That second version is a two-sided argument and it works because the admission up front earns your trust for everything that follows.
How to Use This in Your Next Pitch (Without Sounding Like You Are Terrible at Your Job)
Now, the obvious worry is: if I start telling clients about my weaknesses, will they just go somewhere else? The short answer is no, as long as you follow the rules Phill laid out on the show.
First, the weakness has to be real but minor. Guinness is slow to pour. That is annoying, not catastrophic. You are not telling clients your last three campaigns flopped. You are telling them something like, “We are a small agency, which means you get the founders in the room, not the junior account exec.” The flaw is genuine. The reframe is immediate.
Second, the weakness should ideally flip into a strength. The slow Guinness pour becomes a ritual. The small agency becomes a founder-led service. Liquid Death’s aggressive branding becomes the reason their water stands out in a fridge full of identikit bottles. The flaw is the feature.
Third, it has to come early. If you bury the admission at the end, it looks like damage control. Put it up front and it looks like confidence. There is a world of difference between a brand that says “yes, we know, and here is why it does not matter” and one that gets caught out and scrambles to explain.
At Prohibition, we have started doing this ourselves. “We are not the biggest agency in the North. We are not trying to be. What you get is Will and me, actually in the room, actually doing the work.” It feels honest because it is honest. And honestly? The clients who run away from “small” were going to be a nightmare anyway. Two-sided arguments are a filter as much as a persuasion tool.
Why It Works: The Trust Shortcut Your Brain Cannot Resist
The reason two-sided arguments and the pratfall effect are so powerful comes down to how our brains process trust. When someone only tells you good things, a little alarm bell goes off. We have all sat through pitches where everything is “award-winning” and “industry-leading” and thought, “Right, what are they not telling me?”
An admission of weakness switches that alarm off. It signals honesty. And once your audience believes you are being straight with them, they lower their defences and become far more receptive to your actual message. Psychologists call this the credibility heuristic. The rest of us call it “not being full of it.”
Hear Phill Agnew Explain It Properly
I have given you the highlights, but Phill goes much deeper on the episode, including more examples of brands that have nailed this and a few that got it spectacularly wrong. It is one of those conversations where you walk away thinking differently about your next campaign.
Listen to EP 104: Why Liquid Death and Guinness Highlight Their Flaws with Phill Agnew
Available on Apple Podcasts, Spotify and YouTube.
P.S. If you have ever used the pratfall effect or two-sided arguments in your own marketing, I would love to hear how it went. And if you have not tried it yet, next time you are in a pitch, find your one honest weakness and say it out loud before anyone else does. You might be surprised what happens.
Chris Norton is the founder of Prohibition and an award winning communications consultant with more than twenty years’ experience. He was a lecturer at Leeds Beckett University and has had a varied PR career having worked both in-house and in a number of large consultancies. He is an Integrated PR and social media blogger and writes on a wide variety of blogs across a huge amount of topics from digital marketing, social media marketing right through to technology and crisis management.
