If you are doing it right, you know what the Hidden Feature is.
It’s the thing that makes your client fall off their chair.
When they talk about it, their voice goes up an octave and they start waving their hands around in the air.
It keeps them up at night as they worry about it.
It’s their baby of the project and they know, deep down they know, that if it comes to light, it will be the best thing in the project.
This is the Hidden Feature and thi sis the feature that if you make happen will yield the greatest benefit not because you gave them what they want, because you gave them what the need to get better.