Pinecast has no way of knowing exactly where a listener or subscriber is coming from. We try to calculate country using two methods:
Cloudflare's automatic country detection
A GeoIP resolution server
There are a number of reasons why the country may be wrong for a listener or subscriber:
The IP location data that we used to infer the country is wrong.
The user is VPNing or somehow using a proxy.
The user is very near the border of two countries.
The user is using a service like Tor.