I got em balanced today. How do they do it? What does it do?
Balancing is done by spinning the wheel and tire on a machine that measures the balance. Lead weights are added to the wheel in locations they are needed. If one is out of balance, it will wobble while your driving and the road will chew up parts of your tire. Rotation should be done about every 6000 miles. The front tires get more wear because of the turning they do when you steer. Having them rotated helps the front and back tires share this wear more evenly and increase the life of your tires.
Rotating and balancing tires basically increases the life of your tire.