A geofence is a virtual perimeter around a geographic area, such as a hotel, a conference center, an exhibition or any another arbitrary boundary. When a mobile device using a geofence service enters or exits a geofence, the device receives a notification which often is in the form of an alert or a mobile coupon. A geofence notice may be sent to another mobile phone or email account as well. Although a relatively new concept, geofencing is beginning to be used for marketing, security, and anti-theft purposes.
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