Sunday's poker guide explains the tremendous value that can be gained from watching others play poker
"Sweating a poker match involves watching other people play poker online. While to the outsider it may seem confusing or boring, to the informed it is a valuable experience. You can sweat your friend, your coach, but most popularly it is sweating a high stakes match between famous players. "
The article can be found in the beginner guides sub section of poker guides area of the poker section in the sub tabs.