Adam and the salesman

Adam was window shopping, relaxed, daydreaming. But then suddenly a sales man called him over. "Hey you want to buy something extraordinarily?" The salesman asked. "Have you heard of gold medals?" He continued. Then Adam answered: "Not really. What is it?"
"It’s a very ancient recipe for winning. Later research showed that all of the Olympics winners have wore them... It’s only 9 grands, but you’ll end up a champion." 
"Okay. I will buy one."

Now we all know what’s wrong with that salesman argument. Adam, also, looks comically stupid. But the sad thing is that we actually do this kind of idiotic decisions on a daily basis, whenever we skip needed skeptical steps to be sure of the claims made by others, specially when it have sexy tags like, Scientifically validated effects.