Size and reliability are important for geofences that are being used in region monitoring from a mobile app regardless of whether Adobe Places or some other service is used. Operating systems recommend some parameters to keep in mind when creating geofences. For maximum reliability, geofences should have a radius of at least 100 meters. You can create smaller geofences, but entry and exit events might not be generated, or might be generated after the user stops moving for a period of time.
In addition, accuracy and reliability might be reduced based on hardware conditions such as wi-fi being turned off or being unavailable and also on the device's location in relation to hampering GPS signals. For example, mountainous areas, urban settings, and indoor areas can reduce location accuracy from iOS and Android.