I read recently that the sound of sarcasm is different in every language. You might think that verbal sarcasm would be easy to detect regardless of the language, but that's just not the case. This does, however, make sense of a story Arj Barker told about performing in Germany. His sarcasm-based comedy didn't quite seem to hit the mark, and even allowing for the idea that English might have been his audience's second language, this would better explain why they didn't seem to get it: they didn't know how to listen for the English-speaking sarcasm tone.
Mokalus of Borg
PS - Fortunately, on the internet, we can all detect sarcasm in text perfectly.
PPS - Just like that.