To be clear, there's a big difference between seasoning it the night before (salt) and aging. Though salt does pull moisture in the aging process, then natural enzymes break down the connective tissue in the muscle to tenderize. This won't happen overnight and, in my experience, salt does more harm than good. Two ways beef is aged is "Dry" and "Wet" aging. Wet-aging is the by far the most common method used in the U.S. today. Wet-aging involves putting beef in a vacuum-sealed bag to retain its moisture. The reason stores got away from Dry-aging was due TO the loss of moisture which of course it weight/money.