How do online advertisements know where I'm from?

[DBR]

I've noticed that a few of the ads that show up here are aimed at people in the city or country I live in. Not just this site, but others as well--sites that I have not signed up for or given even one iota of personal info to. So I think I can rule out registering or signing up as an explanation.

In order to know this, I assume something, somehow, someway can trace where I am from, and I wonder if this compromises my computer's security in any way.

 

[Tiberius Jim]

I'm going to guess your IP address, but I may be wrong.

 

[Hermiod]

^Generally, IP address ranges can be narrowed down to specific areas.

 

[Starbreaker]

You're the #1 winner in Podunk today!!!

Be with these three girls in Podunk today:

 

[DeafPoet]

Be with these three girls in Podunk today:

That one always makes me laugh. Might be slightly more convincing in a bigger city but I'm always thinking: "Wait a minute, I know everyone in this town and nobody's that hot!"

 

[RandyS]

I've noticed that a few of the ads that show up here are aimed at people in the city or country I live in. Not just this site, but others as well--sites that I have not signed up for or given even one iota of personal info to. So I think I can rule out registering or signing up as an explanation.

In order to know this, I assume something, somehow, someway can trace where I am from, and I wonder if this compromises my computer's security in any way.

Sometimes those pop-ups carry viruses. I got one once. It wasn't serious though. Most of the time they're just ads. Best to just ignore them.