A konjac sponge is basically a cleanser and exfoliant rolled into one. Softer than a loofah and finer than a washcloth, its unique texture gently removes dirt, oil, dead skin cells, and even stubborn makeup. Once all that crap is off your face, your skin is much softer to the touch and looks brighter. Makeup goes on better, too.
Best of all, konjac sponges are so gentle, even those with sensitive skin or rosacea can use them without fear of irritation (unless you overdo it, of course).