I have the travel size version of this product, and it has lasted me aaaages.
I was skeptical about the thought of putting pure powder in my hair. But it works through oily roots really easily, so I don't need to worry about residue being visible. The opening when product is dispensed is tiny, so there is no chance of too much powder exploding over you.
Especially fab when I put it through my hair at night. The next morning I will have extra volume along with fresh hair.