You may not yet have heard of Michigan-based ­Sarcasm, Inc but it would be no exaggeration to say that it may soon be as big a household name as Tesco or Google.

Its product, perhaps the most innovative and original of the century so far, is a punctuation mark for sarcasm. Although ­strangers to the mark might mistake it for a squiggle with a dot inside, the "SarcMark" will soon be turning up in our inboxes every day. The question that will baffle future generations is how we managed to live without it for so long.

It's surprising, given the ­brilliance of the idea, that it has never been suggested before. ­Admittedly, French poet ­Alcanter de Brahm proposed using a ­backward-facing question mark to denote irony in the late 19th century. But that's in no way similar to the scribbled brilliance of the SarcMark. And the fact that US writer and satirist Josh Greenman proposed the upside-down exclamation mark as a "sarcasm point" in an article for Slate magazine in 2004 is equally ­immaterial.

The existence of numerous alternative solutions already in use, from emoticons such as :P, ;) and :) to pseudo-html markers such as [/s] and </sarcasm>, is unlikely to be an ­obstacle to the SarcMark's overnight success.

The real breakthrough of ­Sarcasm, Inc is the realisation that, ­despite having used sarcasm and irony in the written word for hundreds of years, humans are simply too stupid to consistently recognise when someone has said the ­opposite of what they mean. The SarcMark solves that problem, and you can download it as a font for the reasonable price of $1.99 (£1.20). Our prayers are answered.