If you are talking about making the demo interactive, I would say that - of course, for a UX professional - it depends. In general that might be a good idea if your product is one that invites particularly interesting interactions.
Depending on your users and your product, people are less likely to care about interacting with, say, a financial product, unless there is something really cool about how you interact with it. If it's just a demo of how your product works, a video/animated demo is probably fine, and likely cheaper to produce.
If there is some totally cool control/interaction within your product that makes it stand out, it might be worth letting people play with it. But making them take action after action through a relatively standard demo might be more annoying than interesting - save that for the tutorial.