Leaving aside warning signs such as emoticons etc., this is the issue with sarcasm, and I know a few other people have said it here:
Sarcasm is more or less undetectable in text, because it is all about your tone.
Irony, however, if well-crafted can be used in speech OR text, because it is ONLY about the content of what you're saying, not the tone.
That's why Daily Show correspondents (as a stellar example of masters of irony) are absolutely deadpan when they deliver their comedy. It's about what they're saying, not how they're saying it.
Sarcasm is just irony made obvious by tone.
OT: I believe East coasters are generally very likely to understand sarcasm or irony, West-coasters (particularly in California in my experience) don't even have the word on their radar.
Sarcasm is more or less undetectable in text, because it is all about your tone.
Irony, however, if well-crafted can be used in speech OR text, because it is ONLY about the content of what you're saying, not the tone.
That's why Daily Show correspondents (as a stellar example of masters of irony) are absolutely deadpan when they deliver their comedy. It's about what they're saying, not how they're saying it.
Sarcasm is just irony made obvious by tone.
OT: I believe East coasters are generally very likely to understand sarcasm or irony, West-coasters (particularly in California in my experience) don't even have the word on their radar.