Now that I use conditioner, I wonder why shampoo and conditioner come in the same size bottles as a matched set. I use about 1/3 more conditioner than shampoo. That means I'll go through four bottle of conditioner for every three bottles of shampoo. And it will take me that many bottles to get back to a point where I'm starting a new bottle of each at the same time.
Shampoo vs Conditioner
