Dunkin' Used Coffee Scent on Buses to Boost Sales 29%

Picture this: You're half-asleep on your morning commute, slouched against a bus window, when suddenly the smell of fresh coffee fills the air. Your brain perks up. Is someone brewing coffee on the bus? Nope—it's just clever marketing at work.

In 2012, Dunkin' Donuts in South Korea pulled off one of the most ingenious advertising stunts in recent memory. They installed atomizers in Seoul city buses that released the aroma of freshly brewed coffee at precisely timed intervals. The kicker? The scent was triggered to spray whenever Dunkin's radio jingle played over the bus speakers.

Scent Meets Sound

The campaign targeted nearly 500 buses along major routes throughout Seoul. Here's how the sensory ambush worked:

• Dunkin's jingle plays on the bus radio
• Atomizer releases coffee aroma into the air
• Passengers smell coffee while seeing Dunkin' ads on the display screens
• Bus stops near Dunkin' locations, creating immediate purchasing opportunity

The timing was surgical. By the time riders got off the bus, many of them passed a Dunkin' Donuts location within a short walk. And that fresh coffee smell? Still lingering in their memory.

The Results Were Staggering

Store visits near targeted bus routes jumped 16%. Even more impressive, coffee sales at those locations surged by 29% during the campaign period. For context, that's the kind of sales lift most marketing teams would sacrifice their office espresso machine to achieve.

The campaign earned industry recognition too, winning a prestigious Gold Lion at the Cannes Lions International Festival of Creativity. It became a case study in multisensory marketing—the practice of engaging multiple senses to create stronger brand memories.

Why Smell Works So Well

There's neuroscience backing this strategy. The olfactory bulb, which processes smells, has a direct connection to the limbic system—the part of your brain that handles emotions and memory. Visual and auditory information has to take the scenic route through other brain regions first.

Translation? Smells hit faster and stick longer. They bypass rational thinking and tap straight into desire and nostalgia. That's why the scent of coffee doesn't just make you think "coffee exists"—it makes you want coffee right now.

Research shows that scent can increase brand recall by up to 65%. When paired with audio cues like a jingle, the effect compounds. Your brain creates what psychologists call a cross-modal association—linking the smell, sound, and brand together into one memorable package.

The Bigger Picture

South Korea has one of the highest coffee consumption rates per capita in Asia. Dunkin' wasn't just selling caffeine—they were tapping into an existing cultural obsession. The bus campaign worked because it met people in their daily routine, right when they were most vulnerable to temptation: tired, commuting, and craving a pick-me-up.

Since then, other brands have experimented with scent marketing in public spaces, but few have matched the elegance of Dunkin's synchronized smell-and-sound approach. It remains a masterclass in understanding your audience, knowing their habits, and meeting them exactly where they are—even if that's on a crowded Seoul bus at 7 AM.