#281 2024 · JCDecaux Spain · Out-of-home advertisingpair-two-problems
JCDecaux made a stranger with 28 followers famous using its own unsold subway ads, to prove subway ads work
the problem
Brands wrote off Madrid's subway ad space as low-value, and subway ad investment fell 7% in a year
background
Madrid's underground carries more than 2.3 million riders a day, but advertisers had decided subway ad space was less relevant and effective than street-level billboards, and subway ad investment fell 7% in 2023. The usual response — sales decks citing reach numbers, discounted rate cards — hadn't reversed the perception.
JCDecaux Spain had hundreds of unsold ad spaces sitting empty across the network at any given time, generating no revenue and proving nothing to skeptical brands. A conventional pitch would tell a brand what the space could do; nobody had used the empty space itself to demonstrate it live.
the move
David Madrid filled JCDecaux's unsold subway ad spaces with the Instagram posts of a real, unknown woman — 28 followers, no fame, no story — and let the campaign run as her account grew, using the ad space as the mechanism of her fame rather than describing the space's reach in a pitch.
the payoff
More than 400,000 impressions in the first week and interactions with 92,000 unique accounts within a month, per JCDecaux's own release; Marina's Instagram grew from 28 followers to over 10,000. Neither source read for this case discloses a brand-signing or media-investment figure, so that claim is not made here.
what came after
'Meet Marina Prieto' won six Cannes Lions in 2024, including a Titanium Lion and the Creative B2B Grand Prix — the first Spanish campaign to win that category — and is now cited in OOH sales trainings as a model for proving inventory value by using the inventory itself rather than pitching it.