Don't set the language of your website based on user location
Microsoft is doing this as well. I google something in english, find an english MSDN entry with english title and preview, but when I click on the link, the language changes to German. I'm a native German speaker but having read about technical topics almost exclusively in english for years, I'm just much more comfortable in english now.What makes it even worse is that often it's not properly translated, but just Microsoft's translation machine applied to the English version. The result isn't very good. And even if it were manually translated, the result would likely end up a mixture of english and German. German is a very nice language, as is english, but what I absolutely hate is the mix of the two, also called denglisch.