Why, you ask? Because it goes on smooth like liquid lipstick does, and stays on forever without any stickiness, only very soft and velvety delicious texture.
The only drawbacks are: it's tricky to apply, one needs a fairly steady hand and the applicator isn't too forgiving. And you can't really touch it up without it getting slightly crumbly. However, given that it never ever comes off, you don't really ever need to reapply.
This post is also brought to you by my Tinkerbell hair !