The Weakness Of Crowds.
A Columbia Univeristy experiment shows that people's rating of a product (in this case, music) is indeed influenced by the opinions of others. Songs received higher ratings from people who were told that they had previously been highly rated than from a similar group without that information.
Because the long-run success of a song depends so sensitively on the decisions of a few early-arriving individuals, whose choices are subsequently amplified and eventually locked in by the cumulative-advantage process, and because the particular individuals who play this important role are chosen randomly and may make different decisions from one moment to the next, the resulting unpredictability is inherent to the nature of the market. It cannot be eliminated either by accumulating more information — about people or songs — or by developing fancier prediction algorithms, any more than you can repeatedly roll sixes no matter how carefully you try to throw the die.
So much for the power of the early adopters, but the real question for marketers is why the followers follow? Does the previous recommendation provide positive reassurance to risk-averse followers or does it encourage conformity for fear of standing out from the crowd?
Furthermore, although wandering around supermarkets has shown to me the astonishing power that best-before dates hold over most shoppers, I wonder how, outside of sociology experiments, do the followers determine how a product or service has been rated?