The New York Times Bestseller List
Cumulative advantage is a powerful side effect of story telling. Get out front, even a little, and you sell more because many people like to invest in a winner. We like to read what other people are reading.
A classic example of cumulative advantage is the power of the Times' list.
Rebecca has a good post about the list but she misses the two key points.
The first: The Times' list is completely fictional. Made up. Divorced from reality. The stated goal of the list is to find (and promote) books that Times editors want people to read, not books that are actually selling a lot. (The editor of the Book Review told this to me years ago). So, they make up 'rules' to appear consistent. When Harry Potter was selling like crazy, they invented a new list so that they could take JK Rowling's books off the real list. When diet and other books started selling a lot, they made up a new ghetto (miscellaneous) for those books. When books started selling in places like Wal-Mart (thus driving the snootiness factor down) the Times penalized sales in chain outlets. And books like the Bible are banished because they're not current enough.
The second: the list is easier to manipulate than ever before. The identity of reporting stores is becoming easier to find and the leverage of being on the list is high enough that authors can profit just by buying their own books in enough quantity.
The best part... it doesn't matter. Cumulative advantage is so powerful that even though the accurate reports of book sales often completely contradict the Times list, authors and others still obsess over it. We're always looking for clues, especially in crowded markets.
The thing that amazes me is that there are so few bestseller lists in other markets. Consumers want them. Producers can leverage them. It's an opportunity, I think.