Brandzooka determines where to serve video impressions by reading IP metadata on devices. While rare, the metadata of a device can be tagged with a geographic location that is different than where the device resides.
For example, when someone flies from one city to another and turns on their device when they land - the IP address may not update immediately, and that person may be served an impression meant for the location they left. IP addresses can take up to 24 hours to refresh, which can result in stray impressions delivered outside of your target area.
If you ever see an abnormally high number of impressions outside of your geographical target on the heatmap, please chat in or contact support@brandzooka.com for assistance.