I have a site that has 60% of it's user base being outside of North America... It would aid me greatly if I could display targeted advertising based on the visitor's country specific domain (if it resolves...)

I heard from someone that with NT hosting this is a hard feature to come by since it doesn't cache previous lookups -- and hence puts "too much of a load on the dns server" so web hosts don't bother turning it on?

If that's the case then I'm looking for a unix host that has this feature and good prices for a site with 10-20GB a month of traffic..

Thanks for your time all..

Swamper.