Call me weird, but I hate when a program or service uses regions or locales to determine stuff like temperatures or languages.
First of all, it often does it wrong - especially when using geographical location, which is one of the dumbest idea I've seen in computing. GPS fails when people are traveling (just because I'm in Germany right now, doesn't mean I want to see websites in German, etc.). GeoIP fails for various reasons, including VPNs and weird ISP shenanigans.
Second of all, as a person fluent in English, I especially don't want to see a translation of your originally English site. Most software and website translations suck hard. My most common gripe: using the same word in translated language for things named by different words in original, or vice versa.