the idea of demo is, that around 70 start.ups unveil their companies in front of broad a venture and press audience. everyone gets around 6 minutes on the stage to tell their message.
besides all the press-fuzz, attending demo does not at all guarantee you bringing home plenty of vc money and it´s pricy.
however, there is a great thing about demo for every start.up.
all the pitches can be followed live (no firefox on windows though) or offline. that gives plenty of examples, how others present their company. something you normally would not get a chance to, because that happens in the closed offices of VCs.
there are good and bad examples, sure. but what a resource to learn to focus. to bring across the message in 6 minutes, how to present and make anyone want know more about you and your start.up.
for anyone who likes to search the archives, system one, an outstanding austrian high tech start.up, was there in 2006.