Great post from Mitchell Ashley that accurately describes most demos I have seen (I've even been guilty of giving a few of these):
Most bad demos are what I call "functional decomposition" demos. You know what I'm talking about -- after some perfunctory sales questions, the demo conversation goes something like this...
"This is the blah screen. The blah screen is used to create blah's. You can have an unlimited number of blahs, and can name blahs any way you wish.
Pushing the Create button opens up the window where you enter the name of the blah, and all the attributes of the blah you want to create... the blah type, a description of the blah (it can be as long a description as you wish), etc., etc. I won't go through all the settings on this screen right now, but you get the idea here about how to create blahs.
Next we have the list blah screen where we list all the blahs in the system."
... and so on, and so on. It's a description of the product, a feature walk through, and what everything does. It's like a verbal User Guide told to people who probably never wanted to read the User Guide in the first place. Not interesting, very boring and it doesn't connect with people.
Read the rest of the post here for suggestions on giving a good demo that connects with the audience.