Lets also not negate the fact that for many 'non adult' companies, geo-targeting to them means simply providing a .com .es or .co.in domain extension
It is therefore realistic to expect them to beleive anyone typing overture.com into their browser is a US citizen thus, your results only display on the US site
Afterall, only Indian citizens will type overture.co.in into their browser and they dont know about .com's LOL
Just another of the oddities of marketing with non adult companies, the vast majority of them, we have found over the last 12 months really arent as tehnologically advanced as us in the adult industry at the present time.