Showing different things to different types of visitors

[uhzoomzip]

I am wanting to set up my site to show appropriate advertisements to appropriate visitors.

I have a site that gets a large number of international visitors (I am in the US) and I am running US only offers from that site.

Can anyone help me with where to look to understand how I can show specific ads to the various countries?

Thanks in advance.

[phranque]

geolocation is a slippery slope.
this WebmasterWorld thread links to a good study of this subject:
[webmasterworld.com...]