Here's a great product tour. I guess they assume all their demo visitors already know something about why they would need the product because it dives right into it...

Lyris HQ

What I really love about this demo is, you're immersed in the product from start but the narration is all about higher-level topics like productivity and insight. Perhaps their audience already knows the business case and so this allows them to see the product without a bunch of dull screen shots. Nice and fast too with a clear call to action.