said by jat 
:However, the geolocation services obviously use other techniques as well. For example, GeoIP guesses (correctly) that my IP is from Burlington, Ontario, Canada, despite the fact that TekSavvy doesn't advertise that anywhere. So how do they know? Well, GeoIP's FAQ claims that they have affiliates that send them an IP address and geographic location of users who sign up for their websites. So even if the IP belongs to a US company, as soon as you sign up for a website affiliated with GeoIP with your home address, your IP will be labeled as Canadian again.
Well, in that case, they probably think there's a lot of Canadians that live in 90210. But interesting, I didn't think Geo-IP services went that far into things. 
