A virtual perimeter drawn around a physical location or area. When a device enters or exits this boundary, it can trigger data collection, an ad impression, or an analytics event.
Geofences are the trigger mechanism behind location-based marketing: a retailer might geofence a competitor’s parking lot to serve an ad the moment a device leaves it, or geofence their own store to confirm an ad exposure led to a real visit. It’s a real-time, event-based tool distinct from mobility data, which analyzes broader aggregated visit patterns after the fact.
Further reading: Geofencing for marketing · Geo layer
