#995 2025 · Daangn (Danggeun Market / Karrot) · Hyperlocal community platform (mobile)
Daangn found the missing by alerting only the 1.5-km radius, not the whole city
the problem
Korea's police missing-person alert reached every phone but no one near the sighting — so frequent it had become noise
background
South Korea reports roughly 60,000 missing persons a year, and the National Police Agency ran a Missing Person Alert that pushed the notice out broadly by TV, radio and general phone alerts to catch as many eyes as possible. Because it was not targeted geographically, the people who actually received it were spread across the country while the neighbors close enough to act were not among them; and because such alerts were so frequent, the public had learned to swipe them away without looking.
Blasting the alert more widely — the instinctive fix for a broadcast system that was missing people — would only make the fatigue worse. The reach was not the variable that mattered; geography was.
what everyone would do
For any alert system failing to find people, the standard fix is to push the message harder and further — increase reach, repeat it, go to more channels — on the assumption that a missing person could be anywhere and that only volume can guarantee the right eyes. But a broadcast with nothing to distinguish the urgent ping from yesterday's noise gets filtered out wholesale, and every extra recipient far from the sighting adds nothing.
what they saw
The people able to find a missing person are not the faraway masses but the neighbours within walking distance of the last sighting, so more reach is not more help. Broadcasting loudly teaches everyone to ignore the pings; restricting the alert to a 1.5-km circle keeps each notification rare and therefore actionable.
the move
Daangn signed an MOU with the National Police Agency and tapped the police's missing-person API every ten minutes, then pushed an alert only to app users within a 1.5–3 km radius of where the person was last seen, shown on a map with comment, reaction and share tools for eyewitness reporting. Where the state broadcast to everyone, Daangn intentionally broadcast to almost no one — precisely the neighbors best placed to walk past the last-sighting spot.
why it works
An alert only saves someone if a person who can act receives it. A nationwide broadcast reaches millions, but every marginal recipient is too far away to do anything, and a stream of useless pings teaches everyone to swipe alerts away — fatigue steadily deletes the value of the whole channel. Daangn's tiny radius guarantees the recipient is the neighbour who might actually pass the last-seen spot, where a sighting is plausible; because the alert fires only when it is locally actionable, each one stays salient instead of melting into noise. The state's blunt system had the effect of drowning out the one person who mattered, so Daangn won by doing less — the reduction in reach was itself the mechanism.
the payoff
Entry's own figure: 1,233 missing neighbors located in a month; the alert took Korea's top ad Grand Prix and an ADFEST Silver Lotus.
where it breaks
It needs enough people inside a 1.5-km circle for one to act; in sparse rural terrain even the nearest neighbour may be too far or too few, and it only matters in the first hours before the person leaves the micro-area. It depends on the state ceding its alerting role and exposing its missing-person API, so jurisdictions that will not partner close the door entirely. Pinpointing a location to strangers also raises privacy concerns that could cap how tightly the radius can be drawn.
what came after
The partnership positioned Daangn not as a marketplace but as life-saving civic infrastructure piggybacked on its existing hyperlocal data layer, and the KNPA API link remains a live product feature rather than a one-off stunt.
references
- [1]Chosun English — Korean National Police Agency Partners With Karrot to Share Missing Person AlertsThe Chosun Ilbo, 2025chosun.com
- [2]adobomagazine — ADFEST 2026 Lotus Awards: Indian Grand Lotuses and Innocean's Come Back Home for Daangn takes Silveradobo magazine, 2026adobomagazine.com
Widely retold, only partly documented. Filed as hearsay.