Once you're famous, you get inundated with offers to appear in ads.
But which ones to choose? Should you peddle soap or Siri? Should you declare your love for Buick, while secretly pootling around in your Mercedes?
Stephen Hawking made an interesting choice to advertise auto insurance -- Go Compare's online auto-insurance comparison service, to be precise.
This U.K. brand's ad campaign has long featured Gio Compario, a portly opera singer urging people to, well go compare auto insurance rates.
You might not imagine that this would be an erudite scholar's first choice for an endorsement.
Ah, but in this ad, Hawking gets to suck the opera singer into a black hole.
And who doesn't know at least one authority figure, former lover, or plain annoying human being who might deserve such treatment?
For myself, the highlight of this quite joyous piece is the laugh that Hawking offers at the end.
There is something quite shivering about the coolly hawkish way Hawking offers: "Ha. Ha. Ha."
He told the Daily Mail: "I confess I am a fan of the Gocompare.com adverts, but I am also an opera fan, so I was delighted to be given the opportunity to help save the nation and silence Gio."
It's best not to get on Hawking's wrong side.