INMA_A01.QXD

The long tail concept

The long tail conceptis useful for considering the role of Product, Place, Price and

Promotion online. The phenomenon now referred to as the ‘long tail’, following an arti-

cle by Anderson (2004), was arguably first applied to human behaviour by George

Kingsley Zipf, professor of linguistics at Harvard who observed the phenomenon in word

usage (see http://en.wikipedia.org/wiki/Zipf%27s_law). He found that if the variation in

popularity of different words in a language is considered, there is a systematic pattern in

the frequency of usage or popularity. Zipf’s ‘law’ suggests that if a collection of items is

ordered or ranked by popularity, the second item will have around half the popularity of

the first one and the third item will have about a third of the popularity of the first one

and so on. In general:

The kth item is 1/k the popularity of the first.

Look at Figure 5.4 which shows how the ‘relative popularity’ of items is predicted to

decline according to Zipf’s law from a maximum count of 1000 for the most popular

item to 20 for the 50th item.

In an online context, application of this ‘law’ is now known as ‘the long tail’ thanks

to Anderson (2004). It can be applied to the relatively popularity of a group of web sites

or web pages or products on an individual site, since they tend to show a similar pattern

of popularity. There are a small number of sites (or pages within sites) which are very

popular (the head which may account for 80% of the volume) and a much larger

number of sites or pages that are less popular individually, but still collectively impor-

tant. Returning to the product context, Anderson (2004) argued that for a company such

as Amazon, the long tail or Zipf’s law can be applied to describe the variation in prefer-

ences for selecting or purchasing from a choice for products as varied as books, CDs,

electronic items, travel or financial services. This pattern has also been identified by

Brynjolfsson et al. (2003) who present a framework that quantifies the economic impact

of increased product variety made available through electronic markets. They say:

PRODUCT

The long tail
concept
A frequency
distribution suggesting
the relative variation in
popularity of items
selected by consumers.

Figure 5.4 Zipf’s law, showing decrease in popularity of items within an ordered

sequence

1 50

0

Position of item in sequence

Relative popularity

200

400

600

800

1000