The Behavioural Science Behind “Share A Coke”

2018 marks the fifth US summer of Coca-Cola’s “Share A Coke” marketing campaign, when the soft drinks giant releases thousands of limited-edition bottles showing names, places, occasions, or even song lyrics. It’s probably the most famous, and longest running, mass personalisation campaign in the world, and Coke have regularly credited it with big returns. Back in 2014, following its successful launch, the Ogilvy-run campaign was linked to Coca-Cola’s first sales increases in a decade.

What are the behavioural roots that have made Share A Coke so successful?

Limited edition packs are nothing new – for years Coke, and many other brands, have run tie-in promotions to major events (like the Olympics or World Cup) with pack switches to match. Slightly rarer are campaigns where the pack regularly changes and anticipating the new designs is intended to be part of the appeal.

Pepsi’s LIFEWTR bottled water, for instance, releases new bottle art every few months, created by emerging artists. Coke itself tried a similar ploy with its ill-fated 90s launch OK Soda, whose cans featured work by indie comics artists. It’s probably no coincidence that both these brands were specifically aimed at a then-sought-after demographic, Millennials for LIFEWTR and Gen X for OK. Place your bets on who’ll be first to launch a drinks brand for Gen Z whose packs automatically update with the latest memes…

Demographics aside, these packs are all relying on a particular behavioural trigger – scarcity and a sense of exclusivity. If we think something is scarce, it can become more valuable or desirable. Limited-run packs appeal to the same heuristic that “only 2 rooms left” notices on hotel booking sites do – the fear of losing out on an opportunity. With LIFEWTR, there’s also an appeal to the collector mentality via brand loyalty – regular customers get to see all the new designs.

The genius of Share A Coke is that it turns these concepts completely upside down.  With 1000-plus variants there is no way NOT to miss out. There’s also no way to know what’s out there. And it’s not about personal relevance, either. Your chances of finding your own name, or even a name relevant to you, are very low.

Something else must be in play. Confession time: at first, we at System1 were bamboozled by the campaign ourselves. Looking through a narrow lens of behavioural heuristics, we initially didn’t expect it to do well. When it did, we realised we needed a rethink.

The key, as is often the case with product and pack innovation, is Fluency – the speed of recognition and processing of information. In this case the information Coke’s brand assets – its bottle shape, red colour, logo elements, font, etc. Coke, obviously, has remarkably strong assets, which gives it a platform to innovate few other brands share.

Studies – and our own market research database of high-scoring concepts and ideas – suggest there’s a sweet spot for Fluency and innovation. You need a large dose of familiarity (to ensure high Fluency and rapid processing of the new thing) and a small dose of novelty – to create surprise and excitement. In our work we recommend aiming for 80% familiar, 20% new.

Share a Coke is a perfect execution of Fluent Innovation in the packaging sphere. A hugely familiar wrapper (the Coke design) around an excitingly new shell (the name). And the real stroke of genius is that because the names you see constantly change, there’s no wear-out. The surprise never becomes familiar itself: the pack stays Fluent but also keeps on being Innovative.

Can you pull this off if you aren’t one of the world’s most famous, distinctive, and well-distributed brands? It wouldn’t be easy (though there have been imitators, like Snicker’s “moods” packaging). But the basic principle of “80% familiar, 20% new” is solid no matter your size – always make yourself Fluent but remember to build in surprise.


At System1, we help advertisers make confident, creative decisions that lead to transformational business results. Our powerful ad testing platform (Test Your Ad) and our idea testing platform (Test Your Idea) help brands predict the commercial potential of ads and ideas. Complementing TYA and TYI is Test Your Brand, our brand monitoring tool which measures the impact of ads and ideas on brand health, ensuring long-term brand growth through predictive success.

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