I have been researching a lot of video demos lately in order to develop our own for PIER. In that process you see a lot of good and a lot of bad video demos. I think the tenancy of some companies is to be too self-absorbed in their products, especially in the Software as a Service biz (SaaS). They make the demo that's too lengthy, too full of jargon, too....boring.
Then I found Angelsoft's video demo. It's simple. Fast moving. Interactive. And most of all, captivating. I have watched it several times now. I actually get what they do. For new media, this is a great example.
Angelsoft 3.0 Introduction Video from Angelsoft on Vimeo.