Geofencing

Geofencing is a kind of virtual alert system based on a geographical line or lines drawn on a map. So if you wanted to determine if a person entered a particular supermarket aisle, you would outline that aisle with a geofence, and as a person with a location-enabled smart device entered they could be tracked or credited with a visit. A loyalty count, but you don't need to check-in to anything. A big plus.

It's about more than just getting close to something, its about crossing boundaries. Much more about the concept and recent thoughts about it in a recent Readwriteweb post. An simple but important concept in location based systems and geographical information systems.