Couldn't have put it better myself:

"For advertising to be effective, information has to be expensive to produce and expensive to distribute. Under such conditions, a brilliant product can indefinitely languish in obscurity despite its brilliance, simply because there is no way of getting word out about it. On the other hand, when it becomes trivial for pretty much anyone to produce and broadcast any sort of information, the notoriety of a product becomes much more a function of the brilliance of the product and much less a function of the size of the centralised marketing push."