Even if you are selling embalming fluid, taking direct commercial advantage of tragedy is tasteless.
Since the beginning of time, people have used death as a brand building opportunity. The first time a group of our ancestors were savaged by a cave bear, you can be sure a slick salesman was there hawking a magic cave bear repellent stick.
There is less of a taboo around hijacking a joyful moment, but it still seems a little cheap. I never particularly appreciated my toothpaste wishing me a happy birthday. I am sure Her Majesty will be even less impressed with downmarket vitamin peddlers celebrating her ninth decade.
From a commercial and strategic point of view, this is about when, how and if borrowed attention is appropriate. Put crudely, borrowed attention means sliding your brand message in front of something that has large scale interest.
All the big 'case studies' of 'real time' content marketing are extreme cases of borrowed attention.
The Oreos Super Bowl 'black out' Tweet and the same from Arby's over Pharrell's hat are cited so often that canny clients and colleagues anticipate it and threaten 'if I hear that one ever again...' to keep these fossil faux successes out of the conversation.
Borrowed attention looks like it excites people, especially on Social. But it is just a bit of fun.
It is doubtful one more Oreo was consumed because of the Super Bowl jape, or even a single cookie snob added the brand to a repertoire. It made existing fans, who probably are scoffing as many Oreos as they can, smile - the few that saw it anyway. And it gave marketers and press something to crow about. So no harm done. Cheap, fast, and why not.
But was it strategic? Was there any substantial brand or business benefit to that Tweet? No.
So if a real time opportunity comes along, that is somehow brand relevant, and its cheap or free to do something, have a go. Oreos are playful snacks, and appear at some Super Bowl parties so have at it. Arby's does have that hat for a logo. So, fine. Do it - you will not hurt anyone. You might even be able to build a career on the conference circuit.
On the other hand, something definitely not to do is borrow, or rather exploit the death or life milestone of a celebrity in almost all cases.
The tragic, young passing of one of the most important multitalented forces in popular music has been abused across Social by consumer tech, breakfast cereals and all manner of products completely alien to anything purple.
What brand could have a right? His favourite guitar. A brand that he made or else that he made his own could have a right to mark his passing in media. But only in a small, simple, truly heartfelt way.
Or a long term commercial and personal partner. When Jay Chiat, a personal friend of not just Steve Jobs but many Apple people - as well as the head of Apple's lead agency died simple, tasteful full page ads were placed in memorial.
The same rule applies to birthdays. If the individual involved has made something or made something their own from a brand, then maybe. Just maybe.
So if Corgis were a brand rather than a dog breed, they might consider doing something small to say thank you to Her Majesty. Then ask their doggy selves: 'Is this in the best of taste?' Before leaving it alone.