Drying your laundry quicker - dryer balls get in between the sheets/towels/clothing to allow warm air to reach more surface area and dry your laundry more quickly.
Making your laundry soft and fluffy - laundry dryer balls roll around with your laundry and help fluff up the laundry and keep your clothing, towels, and blankets soft.
Keeping your laundry chemical-free - when you use dryer balls with your laundry you no longer need to use liquid fabric softener or fabric softener sheets that are full of chemicals. You can instead go chemical-free!