A prophecy that comes true, simply because of the fact that it has been made; one of the primary ways that
the media influence society by preying on people's desire to be where the action is and follow
trends. For instance, if a large number of stock analysists pick FOO as a "rising stock" for the week, sure enough, the price will go up because everyone wants FOO because it's a rising stock. If a few public figures start wearing clothing label BAZ because they say they're the coming new trend, then sure enough, they will be the coming new trend because everyone wants to wear BAZ like these public figures.
binarydreams: the "perfect example" you give is
not a self-fulfilling prophecy. The Oracle makes the statement knowing that it will be come true. A self-fulfilling prophecy is a prediction that the prophet is not absolutely sure will come true, but by the mere fact that (s)he makes it, assures its outcome. It's not a prophecy if you know it's going to happen.