Spooky, isn’t it? I see the same thing when I visit certain websites. It’s not always about “sexy singles,” but they frequently nail me down to the Seattle area.
There are a couple of ways this can happen.
You told them
The most obvious is one we often overlook.
Ever register with a site? At a minimum, I’ll bet it required a city, state, or postal code. Well, you just told them where you are. That’s now information that the site (and possibly other sites operated by the same entity or entities) can use to customize your experience. That “customization” could include local news, weather, and yes, even advertising.
In most cases, all it takes is a postal code. If a site has that, and passes it on to other sites or advertising services, then it’s trivial for those sites and services to know – at least in general terms – where you are.
Your ISP told them
… it’s nearly impossible to determine the specific location of a computer based on only its IP address.
As I’ve discussed in many other articles, it’s nearly impossible to determine the specific location of a computer based only on its IP address. The publicly available information about IP addresses only resolves down to the ISP that assigned it. If you need to get more detailed, you need the ISP’s help – and typically they won’t help without legal requirements.
But even without the ISP’s help, you do have something: you have the location of the ISP.
In fact, that’s exactly how I get located when I’m at home. Even though I’m located well outside of Seattle, my ISP is based there. Hence, ads that use “geo-targeting” based on the IP address resolve to the greater Seattle area.
They can get it wrong, too. I’ve had several ISPs over the years in this same place, and location services have at various times reported that I’m in:
- Southern California
- Portland, Oregon
Even the last one, which is indeed correct, narrows down my location only to somewhere within 18 square miles.
The most egregious are cases where they attempt to geo-target an AOL customer. Do a lookup on AOL’s IP range – it looks like every AOL customer lives in Manassas, Virginia, regardless of where they really are.
Google told them
I say Google, but in reality, this could apply to any service which includes geo-location information, and probably applies equally well to Apple, Microsoft, Facebook and others.
This information can be collected from known Wi-Fi hotspots and also from mobile devices that include GPS.
It should be no surprise that GPS-enabled devices have the ability to determine exactly where you are. That’s their point, after all. When the information from these devices is associated with your Google, Apple, Microsoft, or Facebook account, that information can be applied or correlated with your internet access using other devices – like your desktop computer.
That is shared anonymously with advertising networks, which show you ads that relate specifically to where you live.
So the bottom line is that advertisers can often (but not always) make a reasonably intelligent guess as to your general location. It’s nothing new, really, and certainly nothing to be concerned about.