JCDecaux - Meet Marina Prieto
JCDecaux Spain challenged DAVID Madrid to demonstrate outdoor advertising's immense potential and effectiveness. The client wanted to prove OOH could create a viral sensation and amplify a voice, even without branding or calls to action. The goal was to generate significant public buzz and B2B interest in JCDecaux's media spaces by turning an unknown individual into a national talking point.
Creative Idea
JCDecaux turned a 100-year-old into a viral sensation using only outdoor ads to prove the medium's power.
JCDecaux filled Madrid's subway stations with photos of Marina Prieto, a 100-year-old Instagram user, to demonstrate the power of outdoor advertising by turning her into a viral sensation without using any branding or calls to action.
The Grandmother Who Outperformed the Algorithms
Searching for the Unremarkable
To prove that Out - of - Home (OOH) media could manufacture fame from scratch, DAVID Madrid spent four days manually scouring Instagram for the most "unremarkable" profile possible. They bypassed professional influencers to find Marina Prieto, a 99 - year - old grandmother with only 28 followers. Her content was purely authentic - napping, eating churros, and gardening - making her the perfect subject for a "real - time experiment" in human - to - human marketing. When the agency first approached her family, they nearly hung up, fearing the proposal to turn a centenarian into a subway star was a digital scam.
The Mystery of the 800 Posters
The campaign utilized over 800 vacant advertising spaces across the Madrid Metro. In a bold move for a B2B initiative, the agency repurposed 54 of Marina’s actual Instagram posts exactly as they appeared online. There were no brand logos, no calls - to - action, and no explanations. This lack of branding sparked a city - wide mystery that eventually reached 14 countries. The "brand" behind the posters remained a secret for weeks until the reveal at the Effie Awards Spain, specifically timed to target a room full of CMOs and marketing leaders.
Reversing a Subway Slump
The impact was immediate and measurable, reversing a 7% decline in Madrid subway ad investment. Marina’s Instagram followers surged by 39,285%, surpassing 10,000 followers and generating over 1.5 million profile views. More importantly for JCDecaux, the campaign attracted 185+ new brands - including Samsung, HBO Max, and Havaianas - to the Madrid Metro. Existing clients doubled their media spend, leading to all - time record bookings for the Spanish division. Beyond the numbers, Marina became a cult icon for Gen Z, who treated her posters like shrines and requested video shout - outs from as far away as Argentina.
Creative Strategy Deconstructed
Company
JCDecaux possessed vast, unused advertising inventory within the Madrid Metro system. They had the unique ability to saturate a physical environment with content without needing immediate commercial ROI, allowing for a pure experiment in media effectiveness.
Category
The OOH category typically relies on high-contrast visuals, heavy branding, and clear calls-to-action to justify spend. B2B self-promotion usually focuses on reach and frequency data rather than demonstrating creative impact through real-world results.
Customer
Commuters suffer from 'banner blindness' and digital fatigue, often ignoring traditional ads. However, they remain naturally curious and are drawn to authentic, human stories that provide a moment of mystery or delight in their repetitive daily journeys.
Culture
The campaign tapped into the 'granfluencer' trend and a growing cultural appreciation for slow, authentic living. It leveraged the 'mystery box' mechanic, where the lack of information online triggers an immediate social media search.
Company
JCDecaux possessed vast, unused advertising inventory within the Madrid Metro system. They had the unique ability to saturate a physical environment with content without needing immediate commercial ROI, allowing for a pure experiment in media effectiveness.
Category
The OOH category typically relies on high-contrast visuals, heavy branding, and clear calls-to-action to justify spend. B2B self-promotion usually focuses on reach and frequency data rather than demonstrating creative impact through real-world results.
Strategy:
Use unbranded, human-centric mystery to prove outdoor media’s power to drive digital conversation and create cultural icons.
Customer
Commuters suffer from 'banner blindness' and digital fatigue, often ignoring traditional ads. However, they remain naturally curious and are drawn to authentic, human stories that provide a moment of mystery or delight in their repetitive daily journeys.
Culture
The campaign tapped into the 'granfluencer' trend and a growing cultural appreciation for slow, authentic living. It leveraged the 'mystery box' mechanic, where the lack of information online triggers an immediate social media search.
Strategy:
Use unbranded, human-centric mystery to prove outdoor media’s power to drive digital conversation and create cultural icons.
Results
In 2023, subway ad investment went down by 7%. Marina's followers increased by +39,285% (from 28 to 10,483). Marina's engagement increased by +13,404%. The campaign generated impressions in 14 countries. 185 new brands signed with JCDecaux. The campaign resulted in a doubling (x2) of media investment for JCDecaux. JCDecaux also achieved record bookings.
+39,285%
Marina's followers increase
x2
media investment
185
new brands signed
Strategy Technique
Break a Category Convention
JCDecaux defied the convention that OOH needs branding or CTAs to be effective. They proved the medium's inherent power to create virality and buzz on its own.
Explore Technique
Creative Technique
Amplify the Small
JCDecaux amplified an ordinary, unknown individual, Marina Prieto, across Madrid's subway. This demonstrated OOH's power to turn a small, personal story into a viral sensation.
Explore Technique
Craft Breakdown
This campaign's craft is exceptional in its media planning - turning the entire Madrid subway system into a giant Instagram feed for a 93-year-old woman with 28 followers, proving OOH can ignite virality.
Filling hundreds of premium subway ad spaces with one grandmother's Instagram posts was a radical media strategy that turned outdoor advertising conventions upside down.
Transforming Instagram posts into large-format subway ads while preserving the social media UI created a striking visual contrast between digital intimacy and physical scale.
The strategic amplification of Marina's social media presence was designed to naturally go viral, perfectly bridging the physical campaign with digital engagement.
The core insight - that follower count doesn't determine human value - was brought to life through the boldest possible media execution.
The genius lies in the collision between media planning and art direction - without the audacity to fill an entire subway with one person's posts, the visual impact would never have triggered the viral chain reaction.
