The amount of information conveyed with a picture is said to be worth a thousand words. What is the information density of a demo? Pictures, flow arrows, and hand waiving can only get you so far. Demo or die, or sometimes… demo and die.
Don’t you love it when someone in audience gets smart and tries to move you off script… the movie magic ends real quick.
There is something about the medium in which you can poke and paw a slider or a button and have something update in realtime. It either works or it crashes and burns. A working demo is the baseline test of competency, but the only problem is can the demo make it to 1.0? Shipping software is incredibly hard and the history of PowerPoint 1.0 is facinating.
In the early days they had trouble convincing people of what PowerPoint was and what problem it solved. Their mockups were impeccable. The amount of planning and discipline of these 1980s software startups is inspiring. Sweating Bullets is on the must read list for anybody who studies software development.