The browser gets location information via your IP Address. Oftentimes it doesn't work.
I'm on the West Coast on Vancouver Island and oftentimes sites appear to think I'm in Toronto, for example.
According to companies that report on these things:
Accuracy rates on naming the city from an IP address vary between 50%-80%.
Determining the nation of an Internet user is 95%-99% percent accurate, for reasons that have to do with how IP addresses are allocated and registered.
Determining the physical location of the user, down to a city or ZIP code, is trickier and less accurate.
It depends on what the ISP discloses. For example, the island of Ireland is divided between the Republic of Ireland and Northern Ireland which is a province of the United Kingdom. The Republic's TV provider, RTÉ, provides a web TV service, RTÉ Player, which is available in 2 versions, domestic and international. The international service lacks some programming due to licensing issues. In theory RTÉ makes the domestic service available to all the island of Ireland but some Northern Ireland inhabitants UK-based ISPs issue IP addresses from blocks listed as allocated to Scotland over the sea (where the undersea cable comes from), so they are stuck with the international version.
