Are you a student? Imagine passing a note in class which gets intercepted by a professor? He’ll have no evidence after a bit of time.
Are you an executive? Write sensitive notes on documents knowing they will be gone. Have to draw up a quick diagram to get your point across? The writing will be gone even if you lose that piece of paper.
You like playing practical jokes? Slip this pen to your spouse who loves to write “to do” lists.
And if your child has just discovered that writing on the wall, table and or sofa gets the greatest reaction from mommy and daddy you can give this pen to your fun loving kid with a peace of mind that your furniture will have the same design on it as when you first purchased it.