Geofencing ads work by using location-based technology to create a virtual boundary around a specific geographic area. When a user with a GPS-enabled device, such as a smartphone, enters or exits this defined area, the geofencing system can trigger a specific action—like displaying a mobile ad, sending a push notification, or recording the user's presence. Businesses typically use geofencing through mobile apps or advertising platforms that have access to location data. Once the user crosses into the targeted zone, they may receive personalized advertisements or special offers relevant to that location. This approach allows marketers to reach people in real time based on where they are physically located, helping to drive foot traffic, promote local services, or influence purchase decisions near a store or event. The effectiveness of geofencing depends on users having location services turned on and granting permission to access their data.