There are several benefits to having a water-free formula. Many actives will break down in water and lose efficacy; this problem is eliminated with a water-free formula. Without water, preservatives will not necessarily be needed. The product is also more concentrated without all of the extra fillers. The effect on sustainability — Not only are you not using water in the product, but the shipping costs are reduced, and the amount of packaging that is required may also be reduced. All of this helps to lower the carbon footprint for water-free products.