As we all know, affiliate marketing is predominately a Yank thing. Loads of ringtone offers on networks only take US customers and accept US IPs. If you’re international, all you get is this offer isn’t for your area and you’re turfed off to some crappy converting offer like mortgage leads or something.
So I geotarget on my site and don’t show ads to international customers that will let them leave the site. I use the free Maxmind geolocation service and a simple include script. eg