The Economist writes about a meme first expounded by Chris Anderson in Wired:
When people invoke the long tail, what do they mean?
The short answer is a shift from mass markets to niche markets, as electronic commerce aggregates and makes profitable what were previously unprofitable transactions. Consider book sales, which obey a power-law distribution: there is a small number of very popular books, which sell millions of copies, and then a long tail of less popular books. A real-world shop can only stock so many titles on its shelves, so it generally holds those most likely to sell, at the head of the curve: even the largest bookstore carries only around 130,000 titles. But an online store, with no limits on its shelf space, can offer a far wider range and open up new markets further down the long tail. In the case of Amazon, for example, around a third of its sales come from outside its top 130,000 titles.
This has a number of intriguing implications. For one thing, opening up those previously uneconomic niche markets should increase overall demand: as people are better able to explore niches, they are more likely to find things they like, and may well consume more of them. This will then shift some demand, at least, away from hits. Indeed, the long tail reveals the hit-driven nature of the entertainment industry to be, in part, a vestige of scarcity. With limited space on store shelves, media providers are traditionally very discriminating about what they release, and use intensive marketing to generate a handful of hits. The shift towards electronic sales and distribution, howevermusic can already be purchased and downloaded instantly, and movies will be nextmeans that content providers can afford to be less discriminating. The long tail says rather than trying to guess what the market wants, put it all out there and you’ll find demand you hadn’t anticipated, says Mr Anderson.
Perhaps the most profound implication of the long tail, however, is its impact on popular culture.