The litter lasts longer between changes.
I use Biokat's micro unscented litter, and a bag used to last me around 5-6 weeks. With some of this sprinkled in every time I refill the litter box not only has the smell lessened, but the clumps are even better formed, and the litter itself is lasting over a week longer. This product goes a very long way, a pack will last over 6 months for us.