When I was about nine, I saw the way-underrated movie "Explorers," starring a very young Ethan Hawke and River Phoenix (!) for the first time. The movie involves creating a spaceship out of a very hacked-together Apple computer and a Tilt-A-Whirl.
So I wanted to build a thing with my friends. I didn't have a Tilt-A-Whirl, but I did have a Radio Flyer wagon. The original plan, as conceived by my next-door neighbor and myself, involved several Estes rockets, wings, and some twine to act on the control surfaces.
Obviously this was a terrible idea, but we told everybody about the plan. We sold it hard, so that the entire school bus thought we were basically building an airplane.
And we told them about our first test.
And they showed up.
What did we have to show? Well, we had put a cardboard box on top of the wagon and cut-and-pasted pictures of avionics displays out of aviation magazines. A small window was cut into the box, as I had learned windows were important from "The Right Stuff."
The "launch," as witnessed by several of our schoolmates, amounted to us sitting in the wagon and being rolled down a hill at a local park.
Nobody was impressed. Everybody laughed.
Which is why ever since then, I've been hyper-sensitive about launching "cardboard-covered wagons"—products that over-promise and under-deliver.
If a thing isn't ready to do what you want, don't hype it up. This is the way of VC sham economies, but it isn't sustainable and will ultimately poison the relationship between you and your audience.