Sarcasm and satire usually don’t work on the Internet. One cause of this is the lack of out of band signalling via facial expression or tone of voice. Another issue is the fact that in real life people usually know something about the person who they listen to while on the Internet it’s most common to read articles without knowing much about the author. So the reader can’t use “I know that the author isn’t an asshole” as a starting point to determine whether a message should be interpreted literally.
This is really nothing new. The standard in printed communication for a long time has been to use Emoticons (Wikipedia) to indicate emotion and other interpretation that might not be deduced from a direct reading of the text. The Wikipedia page cites examples of emoticon use dating back to 1857 – although the combinations of characters used for different emotions has changed significantly many times. The common uses that we now know on the Internet date back to 1982.
In my experience the symbol :-# is commonly used to note sarcasm or satire. Unfortunately it seems that none of the Internet search engines allow searching for such strings so I couldn’t find an early example of this being used. While I haven’t found a reference describing this practice, I regularly receive messages annotated with it and find that people generally understand what I mean when I use it in my own email. But that is usually applied to a sentence or two.
For a larger section of text a pseudo-HTML tag such as </satire> can be used to signal the end of satire. It seems that a matching start tag is optional as recognising the start of satire is a lot easier once the reader knows that some of the content is satirical. In spoken English a phrase such as “but seriously” may be used for the same purpose, but such a subtle signal may be missed on the Internet – particularly by readers who don’t use English as their first language.
Another way of signaling a non-literal interpretation is by using Scare Quotes – the deliberate usage of quotation symbols to indicate that the writer disagrees with the content that is written. That is common for the case of referencing a phrase or sentence that you disagree with, but doesn’t work for a larger section of text.
A final option is to make the satire or sarcasm so extreme that no-one can possibly mistake it for being literal. This is not always possible, Poe’s Law holds that “Without a winking smiley or other blatant display of humor, it is impossible to create a parody of Fundamentalism that SOMEONE won’t mistake for the real thing” . I think that Poe was understating the case, it is impossible to create a parody of religion that most people won’t mistake for the real thing without signals or context. For an example read LandOverBaptist.org and Chick.com, of course if you know those sites then you will know whether they are satirical or serious – but I expect that most readers of my blog won’t invest enough effort into either of those religious sites to determine whether they are serious or satire.
But satire and sarcasm without signals or a reputation usually fails. One example of success is The Onion which is a long running and well known satirical news site . But even The Onion it is regularly mistaken for being serious – the number of occasions when people forward me Onion articles for amusement are vastly outnumbered by the number of occasions when I see people taking it seriously.
Even when material is known to be satirical it can still fail grossly. An example is the Chaser’s satire of the Make A Wish Foundation . Even material that is well known to be satirical seems to fail when it attacks bad targets or attacks in a bad way. One difficulty is in satirising bigoted people, to effectively satirise them without attacking the minority groups that they dislike can be a difficult challenge.
Finally, when you write some satire and members of your audience don’t recognise it you should consider the possibility that you failed to do it properly. If you can’t get a hit rate close to 100% for people with the same background as you then it’s probably a serious failure.