It's just like a bar of soap, but for your hair! It lasts longer than a normal bottle of shampoo, saving you money, and it also cuts down on the waste of a plastic bottle! There's already been a huge movement to cut down on the plastic straws we use, as we're realizing just how much plastic we're using as a society. I would just say make sure you don't store this shampoo bar where water will continually drip on it making it disappear faster...I learned that one the hard way!