GeoEdge University

How does Geo-targeting Work?

As anyone who works in marketing knows, location is one of the most important ‎elements you can use to target an ad campaign. In traditional media, most ‎geotargeting is implicit; if you buy ads in the San Francisco Chronicle, you can feel ‎confident that only people in San Francisco are going to see that ad.  ‎

In digital however, you can’t assume; YouTube and Facebook are just as easily ‎accessed from Japan as they are from New York.  But beyond controlling cost and ‎ensuring ads only run within the footprint of where the advertiser actually sells ‎their product, geotargeting offers huge opportunities for marketers.  ‎

For one, geotargeting in digital allows for more sophisticated measurement and ‎personalization than was ever possible with traditional media.  And with the ‎proliferation of mobile devices, and the remarkable granularity and specificity the ‎provide in terms of location, geotargeting has never been more powerful.  ‎

But while many marketers understand the value of geotargeting, not many are ‎likely to understand how the technology behind it works.  Having a firm grasp on ‎the technology though is actually critical in this case, as different solutions take ‎different approaches to the problem of determining the physical location of a ‎consumer, and the simplest solution is usually the least accurate.  Just as traditional ‎strategies don’t always translate well to digital, many desktop strategies don’t ‎translate well to mobile.  ‎

Geotargeting Users Online

In online environments, ad servers look at a user’s IP address to figure out their ‎location.  Behind the scenes, the ad server maintains a large database that has ‎every IP address already mapped to its country, state, and postal code.  So, when a ‎request comes in, the ad server strips the IP address from the header of the ‎request, queries this table, finds the necessary location data, and then picks an ad ‎that matches that criteria.  ‎

Now the ad servers don’t create this table themselves, they license it from another ‎company like MaxMind or DigitalEnvoy, whose primary business is geolocation ‎data.   This is no enviable task; IP addresses themselves don’t necessarily have an ‎obvious pattern in the way they are assigned like a telephone area code would.  It’s ‎a bit like solving a mystery, and the geolocation companies use a variety of ‎methods to approach the problem.  ‎

The first thing to do is figure out which ISPs own what IP ranges.  This is public ‎information, used so that an IP isn’t shared among many users across different ‎ISPs.  And since ISPs tend to serve a particular region, usually a country can be ‎assigned to the user with this information alone.  ‎

Now, to figure out state and postal code involves a more complex process. At the ‎core though, the geolocation services build up a network of servers from which ‎they can send out pings, or connection requests, and known physical locations of ‎public entities like universities and government office IPs.  Eventually, with enough ‎data, the geolocation company has the capability to triangulate any IP on the web.   ‎

It works like this – if there is an IP address the company wants to locate, they ping ‎it from a few of their servers, for which they already know the location.  A ping is ‎just a way to test if a computer can connect, and how long it takes to do so, but ‎doesn’t transmit any meaningful data.  Then, by looking at the time it takes each ‎server to connect, it can establish a shared point or origin, and thereby physically ‎locate the user.  It uses the public IP locations to validate their approach and check ‎for anomalies in network latency which would lead to bad data.  ‎

The risk to this approach is that it isn’t always terribly accurate beyond the city to ‎zip code level.  If, for example, you were to use MaxMind’s demo service to locate ‎your own IP, it will likely show you perhaps a mile away from your actual address, ‎likely at the nearest network node, the point at which your computer connects to ‎your ISP’s network infrastructure.   ‎

For this reason, some companies have taken a more direct measurement approach ‎to IP geolocation vs. trying to infer it through ping triangulation.  It’s far more ‎straightforward, but requires a lot more manual effort.  Basically, these companies ‎send cars out to drive up and down every street in the country and log WiFi IP ‎addresses as well as their physical location to populate the same table that more ‎traditional geolocation companies build through technical means.   Google and ‎Skyhook both use this approach. 

By utilizing a premium proxy service, online professionals can view, ‎monitor and validate localized geo-targeted web/mobile content and ads as it ‎appears in each geolocation.‎