In the days when we all had turntables, and there were lots of things to play with, cartridges, tracking weights, bias compensation etc, nobody mentioned cables or distribution panels. The arrival of the CD, with no user variables, seems to have spawned a strange industry of dubious and expensive add ons. One magazine was testing USB cables recently for perceived aural improvements. There seems to be a lot of D/A convertors around, some of which probably have the same chipset in them as the user's equipment and therefore probably don't have any effect even if the user thinks they do.
I'm sure once the magazine reviewer hears the price of some of these products he can hear the improvement they make before he has taken them out of their packing.