At minimum, I assume if I sign up you're going to start emailing me, and I haven't even seen enough to decide if I'm actually interested yet.

Worst case (often the case) those email addresses get collected and eventually sold off to some marketing spam list that just adds more junk to my inbox and adds a little bit more information to some marketing profile about me somewhere.

A video demo would definitely help demonstrate that at least there's a "there" there.