The Lowest form of Punctuation?

If sarcasm is the lowest form of wit, what does that make the SarcMark?

A bargain at just $1.99, you can make sure that your ironic and sarcastic messages in e-mails or other forms of written English do not get misunderstood. Just add the SarcMark© to the end of the sentence and your Uncle is Bob. Apparently, the correct selection of words is just not enough to ensure a giggle at the other end, and now you have to tell people when you are being sarcastic.

But, maybe I'm being a little unfair. Maybe we understand that someone is being sarcastic because of the look on their face, their tone of voice or the incongruity of the situation and what they say - all those things that are lost when writing.

Perhaps one day the SarcMark will be as frequent as the exclamation mark and we will all wish we had bought shares in Sarcasm.inc. I know this is not especially new, so you can review other people's comments in the Guardian.