because it keeps the bathroom cleaner, towels softer, uses less soap and washing powder, leaves the skin smoother and the hair soft and shiny, makes it more comfortable to shave, prevents limescale in the WC and around taps, prevenys soap scum, keeps the washing machine clean, makes it simple to sponge clean windows, mirrors and stainless kitchen appliances without leaving watermarks...
need I go on?
need I go on?