I love them because I can use them wherever I need to keep track of things, and remove them whenever I'd like without worrying about holes or tape marks.
Chalk is great because if Will or Andrew gets hold of it and writes on the furniture or wall, it wipes off cleanly and easily, unlike dry erase markers.
I just used them to label Will's dresser to help him pick out his own clothes more easily in the morning! I took the 8 by 11 sheets and cut them into quarters to be a good size for labeling each half of his dresser drawer.
He loves it, despite my mediocre illustrating capabilities :)