A few years back in Canada the final words from our Captain was that it was imperative we watched the safety demo as it was not only informative, but sometimes very entertaining.
To cut a long story short the cabin crew cracked on with their demo, and indeed as they entered into the spirit of things it was at times funny. This seemed odd at the time, but not as odd as this was the first time ever that to a man everyone on board wathched the demo.
I have mentioned this briefing to a good few people and even though it's result was that everyone took notice of the safety demo, virtually everyone stated that they would never announce such a thing "over here" as it might not be quite what the chief pilot had in mind.
Anyway just a thought about an interesting flight.
tonker