With this cable up to five pedals can be used with one power supply. With two of these in series up to nine pedals and so on. But make sure your power supply has enough power for so many pedals. Just add the mA specifications on your pedals and compare with the one on the power supply. When using a good power supply, the sound is not affected, i.e. there is no increase of hum or buzz etc.
Since there is no need for batteries anymore, this item saves money. Moreover this is very helpful, to build a well organized pedal board. The cable is long enough, such that the pedals don't have to be to close and you can get rid of some big power supplies and extension blocks, blocking space on the board.