Here's a rather extreme example of using marketing hype over everything else: those high priced cables you can shell out real money for down at the local Best Buy? They're not really any better than a coat hanger:

Still, our belief is one thing -- cold hard proof is another, and it looks like a group of 12 self-professed "audiophiles" recently couldn't tell the difference between Monster 1000 speaker cables and plain old coat hangers. Yeah, coat hangers. The group was A-Bing different cables, and unbeknownst to them, the engineer running the test swapped out a set of cables for coat hangers with soldered-on speaker connections. Not a single one was then able to tell the difference between the Monster Cable and the hangers, and all agreed that the hangers sounded excellent.

I'm glad I started buying cables online...