I first thought this was a April Fools joke, but seems these guys are for real - well, for whatever "real" means. Audiophile Ethernet cable. Only €4594 / £3875 / $5886 for a 8 m cable.

http://www.audioquest.com/ethernet/diamond

"The correct direction is determined by listening to every batch of metal conductors used in every AudioQuest audio cable. Arrows are clearly marked on the connectors to ensure superior sound quality. For best results have the arrow pointing in the direction of the flow of music. For example, NAS to Router, Router to Network Player."

OK, so while the google search engine infrastructure, the large hadron collider database and the human genome project are all OK using standard $3 cables, you need a $6000 cable to listen to spotify?