IP address geolocation is the process of localizing the location of a website visitor based on his IP address which is always provided for web browsing or other Internet usages.
IP address geolocation is used by publishers, online merchants and website owners to :
localize and personalize content
comply with local legal regulations
differentiate or limit offers according to countries
manage digital rights
IP geolocation is also heavily used by advertising companies - publishers, ad networks, PPC platforms... - to target ads at various geographical levels.
IP address geolocation is done in real time by comparing IP addresses to an IP address database containing many attributes.
IP address geolocation allows marketers to determine:
US metro code
Some users trick IP geolocation by using dedicated proxy servers.
For more details on the IP geolocation process and accuracy, see IP address database.