I too would be interested to know how others feel about the various geo-location services available to speed things along. Three that come to mind are Akamai, Neustar/Ultradns and the "roll your own" Cisco GSS 4492R. How do they stack up? How good are the various Maxmind files?
Thanks,
Hank
Personally, I have trouble accepting some of the claims the
geotargeting companies have made, such as Quova's 99.9% to the country
level, and 95% to the US state level. ( More info at
http://www.quova.com/page.php?id=132 ) Perhaps I'm just part of the
outlying data; using the "three top search engines" I rarely see them
get the city correct (ie. where *I* am physically located, as opposed
to where the registration data says the block is located), and have
seen some glaring errors for the country in some cases.
Geotargeting has turned into quite a business, and I'm concerned that
people who rely on these services do not fully understand the risks.
--gregbo
Some folks are relying on it for serious purposes. Many Internet
gambling sites use it to avoid serving US customers, for example.
Their risk is criminal liability for the executive -- the have a
strong incentive to get reliable data... Some sports media sites use it
to enforce local area blackouts; though that doesn't need to be
perfect, if it's too imperfect they risk breach of contract and
expensive lawsuits.
For the advertisers, best effort is probably good enough...
--Steve Bellovin, http://www.cs.columbia.edu/~smb
Funny you should mention sports media sites. Not too long ago,
someone asked on usenet how to foil geotargeting in order to watch a
sportscast that was being blocked. The answer was posted not long
after the question. It doesn't surprise me that "the word is out" on
how to foil geotargeting, but it disturbs me that this aspect of
geotargeting is not discussed more. I would prefer it if there were more
openness and transparency about such things (without necessarily
divulging the exact means by which geotargeting can be foiled).
The Carleton paper ( http://www.scs.carleton.ca/~jamuir/papers/TR-06-05.pdf )
goes into some detail on the practical limits of geotargeting, but it
has been difficult to raise this type of awareness among consumers of
geotargeting services.
WRT advertisers, opinions are mixed on whether best effort is good
enough, fraud aside. Some feel any discrepancies are just a cost of
doing business on the Internet; hopefully they have factored
discrepancies into their ad spend. Others are more skeptical. Some
of you may find ( http://blog.merjis.com/2007/10/19/adwords-geotargeting-myths/ )
interesting.
--gregbo
The trouble with a claim of "95%" accuracy is the method of
determining the accuracy
of the measurement has not been indicated, and there are _many_ IPs out there.
With no method of obtaining the statistic indicated: there is no evidence I saw
that 99%/95%, weren't possibly just made up numbers for the purpose of
aggressively marketing a product.
I agree it is not very believable that a geolocation service properly
locates 95%
of all ip addresses to within a state/city.
Due to the existence of various types of proxies and anonymizer services,
visible IP often does not reveal original requestor details.
RIR records give contact information for an organization utilizing IP
space, that's
not the same as the physical location of nodes -- it makes the RIR data an
unreliable source of information for that usage.
This information is not necessarily always up to date in the first place.
Nodes on the very same RIR allocation may be geographically distant.
No more reliable than performing traceroutes to the destination IP,
reverse resolving, and
using pattern matching to search for possible city, state, country
names contained in
the reverse DNS mappings of the hops nearest the target.
(Since providers sometimes include state and/or city names in router rDNS hosts)
On the other hand, it's perhaps the best geolocators can _try_ to do...
Short of geolocation services manually calling ISPs and asking.../
making deals with major ISPs to procure lists of geographic regions and
assigned IPs in those regions.
I suppose that in theory proper geolocation close to 95% of IPs for page access
requests would occur then (provided 95% of page access requests came from
providers they had that type of direct information from)
[nicely off-ops, pre-X-mas 101]
James Hess wrote:
[..]
On the other hand, it's perhaps the best geolocators can _try_ to do...
And they really can't care less about that data. What they do is very
simple, and it maybe explains for you why for instance the big G earns
loads of money: by aggregating data and selling it.
When you go to Amazon.com and you buy something, from your IP, you fill
in your full address details. Then your DHCP expires or for some other
reason your IP changes, and another person gets that same IP, they go to
some other site and fill in their address details. Do this trick for a
couple of hundred rounds. Most very likely the same /24 or some other
size will be re-used in the same geolocation, may that be country, US
state (which actually is just country size compared to Europe), city
etc. After a while you will have a lot of people (they can't care less
about your name though) who have said that when they came from IP
a.b.c.d, that their address was X, as such for IP a.b.c.d you had x%
people saying it was city Y and y% saying it was city Z. Presto, your
accuracy for that IP. Even works when people fill in fake data or use
business/home address (that is why they want you to tag it as such, as
it would screw their stats 
Now combine a couple of thousands merchant site to increase the data you
get, buy/sell it at country/state/city/street level and you have the
best data ever.
That 0.1% of the data that is 'inaccurate' now is the data of proxies
and other multi-city/state/city IP addresses.
Now you know how to earn money by selling something you collected from
simple a site. Now you probably also understand why data from "Social
Sites" is so valuable: all those people fill in all their data, and that
in a structured way, together with a nice link to 'friends' who also do
that, from which you can so statistical stuff about how accurate it is
as most of them live togheter/closeby or talk about it. They don't
really break any 'privacy' with that, they generally can't care less
about who you are, they just care about the statistics, as that is the
data they will sell.
Can't help you any further though if you are still wondering how the two
G man bought their own Boeings 
Greets,
Jeroen
Personally, I have trouble accepting some of the claims the
geotargeting companies have made, such as Quova's 99.9% to the country
level, and 95% to the US state level. ( More info at
http://www.quova.com/page.php?id=132 ) Perhaps I'm just part of theThe trouble with a claim of "95%" accuracy is the method of
determining the accuracy
of the measurement has not been indicated, and there are _many_ IPs out there.
With no method of obtaining the statistic indicated: there is no evidence I saw
that 99%/95%, weren't possibly just made up numbers for the purpose of
aggressively marketing a product.
Well, I use a geolocation service, and as I travel around to many fine hotels and meetings,
I try to check frequently to see if it knows where I am, so I have a few dozen test probes scattered about the globe.
The results are mixed. On US corporate (enterprise) networks, it is typically unreliable. In-room
hotel networks generally get mapped to the right city. Wireless hot spots are erratic - sometimes mapped
to better than a km, sometimes wildly off. People's home networks, generally the right country, frequently the right city.
I would say, overall
- mapping to the right country, probably better than 95% accuracy, maybe 99%.
- mapping to the right city, at least 75% of the time, for sure not 99%, even if you discount enterprise networks.
Of course, your probable error may vary...
Regards
Marshall