How do sophisticated geo-location technologies operate?

Currently the only form of geo-location technology that can be called sophisticated is geo-location technologies that use the translation of IP addresses into geographical locations, based on information stored by the provider of the geo-location service. The figure below illustrates a common model of how this form of geo-location technology is applied:

As the access-seeker enters the appropriate Uniform Resource Locator (“URL”) into his/her browser, or clicks on the appropriate hyperlink, an access-request is sent to the server operating the requested website. As the server receives the access-request, it, in turn, sends a location request (e.g. forwards the access-seeker’s Internet Protocol (“IP”) address) to the provider of the geo-location service. The provider of the geo-location service has gathered information about the IP addresses in use, and built up a database of geo-location information. Based on the information in this database, the provider of the geo-location service gives the website server an educated guess as to the access-seeker’s location. Armed with this information, the web server can provide the access-seeker with the information deemed suitable (e.g. a message along the lines of: “Sorry. This website is intended for the people of Sweden only”, or perhaps provide advertisement specifically targeted at people from the access-seeker’s particular location). There are currently several products on the market utilising this type of systems. This technology is not necessarily prohibitively expensive for larger website operators, nor does it appear particularly difficult to operate.