How are they doing that?

[Adam5000]

I'm used to seeing advertisments on a website with links to other websites (Click here for discount tickets to Disneyland), and I don't have a problem with that.

But lately, sites I've never visited are putting advertisments on the screen custom tailored to me. Flights from (my home town) to Chicago only (insert a dollar amount here). Or Hi! My name is Suzy. I'm from (my home town) too, and I'd love to chat with you (advertising a dating service). And so on.

How are they doing that? I've never visited these sites and how do they know it's my computer anyway?

Deleting the browser history and temporary internet files and so on with internet options doesn't have any effect.

Help!

[Philosopher]

At least in that instance, it sounds like simple geotargeting.

Your IP tells them with a fair amount of accuracy, where you live (at least to the state and often the city). From there it's a simple matter of serving a location appropriate ad.

[LifeinAsia]

It's most likely being done with geotargeting by IP.

I would say it's working quite well- it certainly got your attention.

[Slinger]

My guess it's geotargeting.

[rocknbil]

It's annoying as can be when it doesn't work. :-)

I live in Oregon, but use satellite Internet. I'm always seeing ads for New York or Virginia, depending on what network they have me on at the time.

[maximillianos]

Sometimes they are pretty far off. I see ads for the other side of the state. Kind of funny. It does get my attention though. Big brother. Creepy.