Times have changed and despite customers being ever so difficult to please, they like to catch a glimpse of new products even if they're not ready yet. Call it teasing, science fiction, demo if that makes people talk about you, that works.
Give something to your customers regularly so that they know what you're working and what to expect from you. When you're selling something, do not leave anything as a surprise and set expectations early through a nice demo.
Remember demos can be anything, video, blog post, email, just enough to enable people to talk about it!