consumers.
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Chapter 8 Digital marketing
Box 8.2
Applying the long‑ tail concept
The phenomenon now referred to as the ‘long tail’, following an article by Anderson
(2004), was arguably first applied to human behaviour by George Kingsley Zipf, profes‑
sor 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 dif‑
ferent 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 8.21 which shows how the ‘relative popularity’ of items is predicted to
decline according to Zipf’s law from a maximum count of 1,000 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 relative popularity of a group of websites 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 num‑
ber of sites or pages that are less popular individually, but still collectively important.
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:
One reason for increased product variety on the Internet is the ability of online
retailers to catalog, recommend, and provide a large number of products for sale.
For example, the number of book titles available at Amazon.com is more than
23 times larger than the number of books on the shelves of a typical Barnes & Noble
Figure 8.21
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
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