Numbers mess with your head when buying stuff
If you have a gizmo that nobody will buy, what's the best way to get punters interested? Dancing girls? Whiskey? Nope, although they'd help. No, you need to throw some statistics at customers; impressively long and convoluted numbers that somehow prove why they need your product in their lives.
Don't have any? Not to worry, just make them up. The bigger, the better.
A study released by the Journal of Consumer Research explains a series of experiments that detail how both our preference for a product and working knowledge of it affect our purchasing decision.
You can read a summary of how chinese students were made to look stupid here, but the bottom line is this: if you're marketing a product, promote any numeric values associated with it. If you're a buyer then ignore the numbers, because you probably don't have a clue what they really mean, and instead base your decision on trying before you buy.