Why not cotton?
Cotton running socks are a breeding place for blistering. When the foot sweats in a cotton sock, the sock will absorb the moisture. The foot then moves in the shoe with every step and increases the friction between the foot and sock. This increased movement can cause an increased likelihood of blistering so cotton socks are not meant to be run in!
How does a technical running sock differ?
A technical performance running sock will firstly wick away sweat. They will also allow the foot to breathe and encourage moisture to be drawn away from the skin. Man-made fibres have been proven to reduce the likelihood of blisters. Technical running socks have the ability to retain their shape after multiple washes, offer increased cleanliness and reduce foot odour due to the breathable properties of the sock/shoe.