I realize it's an old post but i thought ill try ask anyway, maybe you can help! so thanks for the tips so far. i am able to use maxmind db and script provided by you but let's say i wanna go with this scenario:

I am doing international facebook ads. I have a problem with my international ads being accepted because of the geotargetting and fb reviewers being either in us or ie. What I want to do is to redirect anyone from US/IE etc. to the main LP offer(without geotargetting) and other traffic I am targeting (let's say it's italian traffic) to the italian version of the offer. I am using prosper and direct linking and I am planning to create many ads in this particular campaign. What I want to achieve is this: When fb reviewers click on my ads geoip script will detect they are in us or ie and send them to the offer without geotargetting so the ad can be approved and there are not problems with destination url. If the users from italy click on my ads the script will detect that it's an italian traffic and it will redirect them via my tracking link to the offer.

What's important: I want this script to pass all specific ad tracking ids from my fb ads to prosper so I can still see what ads have been clicked and how they performed.

I am pretty sure it is achievable for someone who knows php and you seem to be the right person!

Hope it makes sense!

Your help would be much appreciated

cheers :)