In the past when interconnects for audio and visual equipment were analogue the quality of the cable would make a real difference to image and sound quality. However, the same cannot be said of digital interconnects such as HDMI cables. These either work or they don’t work; and there is no difference between a cheap £10 and a £40 cable. The retailers make a small fortune out of these expensive cables as the mark-up can be as high as 80%. In fact, many retailers rely heavily on this as a major source of income due to the high margins and the fact the margins are low on the main products. They know that they can take advantage of consumer ignorance for cables and other accessories as most buyers will not have researched the true value of these.