This was invented by advertising guy Martin Spekter in the 1960s for excited and exclamatory questions. Interestingly, there was a time before punctuation where all the words went together on the page with no spaces.

The following excerpt is from a very interesting ‘very brief history of punctuation’ that is well worth a read.

”In the 3rd century BCE, a librarian in Alexandria named Aristophanes introduced the idea of putting in dots to indicate pauses, like stage directions for people performing texts out loud. Dots of ink at the bottom, middle, or top of a given line served as subordinate, intermediate and full points, corresponding to pauses of increasing length.

Aristophanes’ system became the basis for Western punctuation. A partial thought — followed by the shortest pause — was called a comma. A fuller thought was called a kolon.  And a complete thought — followed by the longest pause — was called a periodos.  These rhetorical units eventually lent their names to the comma, colon and period we know today.

More punctuation followed. Medieval scribes gave us the earliest forms of the exclamation mark. And in the 8th century, Alcuin of York, an English scholar in the court of Charlemagne, quietly introduced a symbol that would evolve into the modern question mark. Ever since, we’ve ended our sentences with one of these three ancient marks, called end marks.

There have, however, been attempts to expand this typographical toolkit, and include other end marks. One such example has made it into dictionaries: the interrobang (‽).

It was created by an ad man named Martin Speckter just over a half-century ago. In the 1950s and 60s, he repped some of the biggest names in publishing, such as Barron’s, Dow Jones, and the Wall Street Journal. Speckter was also a typography nerd, constantly reading books on punctuation and the English language. He and his wife, Penny, collected hundreds of printing presses of all kinds and sizes.”

Amazingly, when people were submitting different designs to his magazine, someone nailed the Rhetorical Mark. This is not so odd, because sentences that take the interrobang are often be rhetorical.