A friend was at Harvey Normans the other day, purchasing a plasma screen TV. After they'd negotiated the price - about $4,400 for an LG highish-res panel, the sales guy then suggested they purchase a special component cable for hooking up their DVD player to the screen to achieve the best quality from their new screen.
For demonstration, he switched the panel to split-screen mode showing the same DVD title playing on each half, but connected by different cables. He was attempting to imply that the marked difference between the two images was due to the use of a "Monster" brand component video cable on one input. My friend gave me a call at the time and explained what the sales guy was trying to say, and commented that the Monster side had better detail in the blacks and looked better than the other half. I told her that it sounded like a scam and hold off for the moment - she could always purchase it at a later date, as he wasn't offering any great deal on the cable.
Subsequently, I worked out that they had hooked up the component output of the DVD player to one side, and the composite output to the other, and was then trying to claim that the improved picture was purely due to the Monster brand cable.
This strikes me as a blatantly dishonest and misleading demonstration - the salesman never stated that the difference in quality was largely (if not entirely) due to the alternative signal format, rather he misrepresented the comparison with the goal of selling an obscenely overpriced cable of dubious benefit over a base-quality component cable.
Why? The 1m Monster cable costs $270.
Methinks a call to the ACCC is in order.