Reference number: CH001043

How does a website / advertisement know where I am?

Question:

How does a website / advertisement know where I am?

Answer:

When visiting some websites you may notice that the page or ad on that page is marketing directly to you. For example, it may be advertising singles in your city or state, this type of advertising is known as geo-targeting and is done by analyzing the location of your Hostname, IP address and/or analyzing the hops in a traceroute of your IP address.

This information gathered often points to the location of your ISP. However, with more sophisticated systems it may be able to also gather the exact city you personally live in.

In addition to getting your location, using the above methods geo-tracking can also be done when registering on a website. For example, after registering the site may store a cookie on your computer and use that cookie to give you more targeted advertising.

How much information can geo-targeting get on me?

The rudimentary form of geo-targeting that obtains its data from your hostname or IP address will not be able to get anything more than your City, State, Country and sometimes Zip code. More personal information such as your full home address, phone number, name, birth date, age, sex, etc. cannot be obtained from your computer without you filling out some type of form first.

Additional information:

• See document CH001044 for additional information about how to manually lookup and find an address associated with a IP address or hostname.