There's an interesting article in Sunday's New York Times about how we arrive at collective judgements of cultural products.
Conventional marketing wisdom holds that predicting success in cultural markets is mostly a matter of anticipating the preferences of the millions of individual people who participate in them. From this common-sense observation, it follows that if the experts could only figure out what it was about, say, the music, songwriting and packaging of Norah Jones that appealed to so many fans, they ought to be able to replicate it at will. And indeed that’s pretty much what they try to do. That they fail so frequently implies either that they aren’t studying their own successes carefully enough or that they are not paying sufficiently close attention to the changing preferences of their audience.
The common-sense view, however, makes a big assumption: that when people make decisions about what they like, they do so independently of one another. But people almost never make decisions independently — in part because the world abounds with so many choices that we have little hope of ever finding what we want on our own; in part because we are never really sure what we want anyway; and in part because what we often want is not so much to experience the "best" of everything as it is to experience the same things as other people and thereby also experience the benefits of sharing.
It's written by Duncan Watts, one of the Columbia University professors whose research on an artificial market for unsigned bands I draw on at some length in the Wise and Foolish Crowds chapter of the book.