Blisters are one of the most common injuries in running sports and other day to day activities. They have become such a normal aspect of life that we tend not to take them seriously, and end up looking for treatment rather than prevention.
Blisters are not actually caused by rubbing, but are caused by shear forces; they look similar but differ largely. For example, place the tip of your index finger on the back of your left hand, now wobble it back and forth, but be sure to keep it still on the same section of skin. Notice that the skin stretches as you move your finger? This is shear and is the underlying cause of blisters.