Geographic Data Reliability

[Lottie]

If most stats packages use the location of the ISPs for geographic data, does anyone know the extent of how misleading these figures are?

e.g. do you have a general idea of how often an US-based ISP like AOL will ultimately pull down a page from a UK website despite the resident actually being located in a different country?

[fischermx]

The main companies that provides that kind of databases are MaxMind and IP2Location, search for them, you'll find a lot of information on their sites.
But to answer your opinion. The per-country reliability is very precise. Per state/region is lower and per-city might be questionable for small cities, but for big cities it might be very precise.

[jaytee]

We use utilities based on these databases for geo-locating users when analysing log files for our clients. They are generally very accurate on a country basis, except for AOL which tend to resolve to the US. It is not difficult to put in special rules for AOL however, as if you do a reverse lookup on the IP address, the name descriptions of the POPs usually have country identifiers.

[GaryK]

The per-country reliability is very precise. Per state/region is lower and per-city might be questionable for small cities, but for big cities it might be very precise.

That's been my experience too.

The only problem I've had has been with the latitude and longitude provided by IP2Location. As an example, the database precisely locates me in Miami, FL. The map coordinates, when plugged into Google Maps, puts my location about a hundred miles east of Miami in the Atlantic Ocean. It does this with some other east coat cities too in both the Atlantic and Pacific. Most of the time though it's quite accurate.

[fischermx]

puts my location about a hundred miles east of Miami in the Atlantic Ocean.

It is because they caught there, while you were on your yacht! ;)