Why It Works: How Stoptober helps millions to quit smoking

Published in Marketing Week, October 2025.

Public service ads are a good place to look for behavioural science tricks to help steer your next campaign.

Ah, here’s October. Bringing golden leaves, darker mornings and cosy nights in. And also: Stoptober. Another invitation to kick that nicotine habit.

Since its launch in 2012, Stoptober has reportedly encouraged more than 2.5 million people to try quitting. That’s a lot of cigarettes not smoked, and a significant reduction in health risk.

Here’s a look at why Stoptober works so well, alongside some other seminal public service campaigns that have stayed with us decades after they ran. Turns out, the best ones work because of their solid behavioural science foundations.

Moments that move us

Part of Stoptober’s appeal lies in the time-bounded ease of the challenge — you’re only committing to a month off smoking. Then you can take stock. Of course, the hope is that if you manage a month, you’ll convert to a lifetime of non-smoking. But making that first step seem as easy as possible is important.

It’s often more effective to change behaviour by making it appear easy than motivating people to want to change.

There is of course a big social element. By coordinating quit attempts and getting people to give up at the same time, Stoptober creates the impression that lots of people are trying to give up. That’s important as we know that social proof — the idea that we look to others for guidance on behaviour — is a powerful force.

But arguably the biggest factor at play is the creation of a trigger moment. This is the idea that setting a trigger or a reminder is needed to bridge the sometimes gaping divide between what we want to do and what we actually do — what psychologists call the intention-to-action gap. Motivation alone often isn’t enough.

Evidence for the power of a trigger comes from a study by Sarah Milne at the University of Bath, and colleagues, in 2002. Exploring what might inspire people to exercise, she recruited 248 participants and split them into three groups, each with slightly different instructions:

• Group 1 (Control): told to note down how often they exercised

• Group 2 (Motivation): alongside tracking exercise, they were given information about the benefits of exercise

• Group 3 (Implementation intention): received the same information as group 2, but also asked to plan when and where they would exercise over the next week

  
  

Milne monitored how much the groups exercised, and the results were clear:

• Group 1 (Control): 35% exercised at least once per week

• Group 2 (Motivation): 38% exercised at least once per week

• Group 3 (Implementation intention): 91% exercised at least once per week

So you can see that giving information had very little effect on how often people exercised. But defining the specific time and place they planned to exercise had a huge impact.

Participants who defined a moment — say, Tuesday after breakfast — were setting up their own trigger. So when Tuesday breakfast rolled around, this served as a reminder to head over to the gym (or another specified place).

And that’s in part why Stoptober works so well. It creates a moment that comes around every year when the idea of quitting is on the table for everyone. It makes smokers at least consider going smoke-free for a month.

It’s the same idea that’s used to such great effect by campaigns like Meat Free Mondays — hey, it’s Monday, let’s skip the steak. Or or Have a Break, Have a Kitkat — having a little rest, time to tuck into a chocolate-covered wafer. In these cases, and others, the trigger moment is a reminder that, yes, you would like to take that action. It works well for any action that people intend to do — like quitting smoking.

Stoptober shows how a time-bound cue can help people bridge the intention–action gap. Marketers can borrow this by anchoring behaviours to specific moments.

Stoptober began 2012, but what if we travel further back in time. Are there any campaigns that still stick?

Charley says…

Anyone aged over 45 might recall a series of public safety ads that ran in the 70s and 80s. Playing out a bit like the opening scenes of a Casualty episode, kids witnessed animations of a small boy in perilous situations — being stalked at a playground, watching pots bubbling over in the kitchen, or straying too close to the water’s edge.

Thankfully his cat Charley, voiced by comedian Kenny Everett, always stepped in with meow-y words of wisdom. The boy then translated for the audience: “Charley says I’d better tell mum where I’m going” or “Charley reminded me I shouldn’t go off with strangers”.

Thankfully, no harm ever came to the little boy.

The campaign is considered one of the most successful public campaigns, and in 2006, was voted the nation’s favourite public information in a BBC survey. That cat clearly held a strong place in people’s minds. Why did Charley stick?

These, and many other public service and brand ads, tap into a particularly effective tool — called a fluent device. This is defined by research agency System1 as a character, created by the brand, used as the primary vehicle for drama in more than one ad across a campaign. In this case, Charley the ginger cat.

There’s some convincing evidence that fluent devices work well. System1 found that 41% of long-term campaigns using a fluent device achieved very large market share growth, versus just 30% of campaigns without them.

Why? Their success is partly based on the concept of concreteness. This is the well proven finding that people are much better at remembering objects they can visualise rather than abstract ideas. After all, vision is the most powerful of our senses.

Fluent devices are essentially a visual representation of an abstract concept. In this case, Charley the cat is the personification of safety. Other examples include Aleksandr the meerkat illustrating the benefits of price comparison for Compare the Market, or the Pepperami animal as a slightly unhinged villain, who conveys the sausage’s punchy flavour.

These characters become strongly associated with the brand or idea, which helps viewers emotionally connect, and more importantly, visualise and thus recall them.

This explains how a generation learnt not to go off with strangers — even if they said they had puppies — and why, more than 40 years later, we can still remember that strange meowyowyow, and the words of sensible advice that followed.

Rhymes that chime

The third campaign I want to look at dates right back to the influenza pandemic of 1918-20. You’ve probably heard the strapline: “Coughs and sneezes spread diseases”. The fact that we can still recall it now is testament to the power of a rhyme.

I’ve been fascinated for a long time in rhyme’s ability to stick in our mind. And in 2024 while researching my latest book, ‘Hacking the Human Mind’, I conducted some original research.

Along with Jon Puleston and Nicki Morley at Kantar, we showed a list of ten statements to 401 nationally representative participants. Half of the statements rhymed (such as “Woes unite foes”) and half didn’t (“Woes unite enemies”).

Respondents were asked to list as many of the phrases as possible. The results were conclusive. People were more than three and a half times as likely to remember a rhyming phrase than a non-rhyming one.

Rhyming has been a significant feature of some highly successful campaigns: ‘Once you pop you can’t stop’; ‘Beanz Means Heinz’; ‘We All Adore-a Kiora’. Given how effective these are at really sticking in our brains, it’s amazing that more campaigns don’t make good use of rhyme.

But it’s lucky that this ad did, as it has undoubtedly helped to reduce the spread of disease for over a hundred years.

And these few government examples are an excellent demonstration of the power of behavioural science. The science is clear: align with how the human brain really works, and your message doesn’t just reach people — it sticks with them, sometimes for a lifetime.