Tech demos are simple in concept:
"Look, we made a thing! Look at the thing working! Now you want the thing, don't you?"
Apple is great at them, Samsung is catching on to them and Microsoft... well, they're trying their hardest.
Satya Nadella, the company's chief executive officer, was recently giving a demonstration of Cortana - the company's voice-controlled PA - at a Salesforce conference.
He was talking about data, sales numbers, systems metrics - dry stuff. But Cortana analytics is supposed to revolutionise this data system! Nadella then proceeded to ask Cortana to carry out a function - and this happened...
Poor Nadella. Maybe he could ask Cortana to find him a replacement voice command service. Like Siri. Or Google Now.
Or just push buttons on a keyboard like it's 2014.