The country, city, state, regions stats are a little off. I know my friend is from xxx but he is coming up as xxx.
It is impossible to be 100% accurate all the time for the geo-location but it is very, very accurate 95% of the time. We update our database monthly to ensure the highest degree of accuracy possible.
One of the biggest problems is with AOL who use a web proxy for all the users so it is very, very difficult to accurately determine the location of AOL users.
Answers to the majority of questions we receive can be found here in the knowledge base.