The average adult human can pay attention for (any guesses?) about 10 minutes, maximum, before he/she needs to be “refreshed” in some way. [Take a deeeeep breath – let it out…] Some researchers comment that a more realistic limit for business people is 5-7 minutes; less if they are seeing a presentation or demo over the web.
This suggests that when you present a demo, you need to break it up into consumable components – chunks – and your chunks should be no longer than 10 minutes, at maximum!
A great way to structure in chunks is to generate and work from an agenda, or road-map, for your demo. You present your agenda at the beginning and return to it after each chunk is completed. The act of returning to your agenda reminds you to summarize and provides your audience with a cue that it is their turn for questions, if they had been otherwise holding back.
I like to use open box bullets for each agenda item initially and then show that each item has been addressed by changing the open box to a “check” or “tick” box – which means that I return to my agenda after each chunk.
If you do the math, for a 1 hour demo you should contemplate having at least 6 chunks and (therefore) 7 uses of your agenda.