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Journal of Applied Mathematics and Decision Sciences
Volume 2008 (2008), Article ID 825156, 8 pages
Research Article

Mathematical Formulation of Relationship between Applied Marketing Effort and Potential Ability of Determining Market Share

School of Economics and Finance, University of Western Sydney, Sydney, NSW 1797, Australia

Received 28 October 2007; Revised 23 December 2007; Accepted 10 March 2008

Academic Editor: Jack Penm

Copyright © 2008 Mokhtar M. Metwally. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The aim of this paper is to formulate the mathematical relationship between firms potential ability and their applied efforts to attract the body of unattached customers. A method is devised in this paper by which management techniques imposed by a particular firm can evaluate its market share. This paper demonstrates the relationship between the applied marketing effort of management and the potential ability of the firm in determining its market share. This paper also investigates the effect of a number of simultaneous marketing impulses on the movement of the body of unattached customers and hence on the size of the market share.

1. Introduction

The study of competition among the few has opened two important (related) fields of research: nonprice competition and customer loyalty in local and global markets. These have been the results of work of many researchers specialized in the field of marketing management. This work includes research by Brunner [1], Taylor and Shaw [2], Heflebrower [3], Glusser [4], Drucker [5], Quelch and Hoff [6], Farber and Wycoff [7], Jaworski and Kohli [8], Clancy and Shulman [9], Ambler [10], Mohammed et al. [11], and Berdrow and Lane [12].

When only two or three firms dominate the market (a situation which is very common in many markets for manufactured consumer goods), consumer loyalty is particularly important for a firm that aims at gaining the loyalty of a certain segment of the market. This segment will not (in the short-run and in the absence of cut throat competition) move to another competitor. We have, therefore, loyal customers who are attached to a particular brand [1315]; and Brown 2001. The implication of this is obvious. If a new firm is to enter a particular market (or an existing firm is to expand its market share), the strategy would be to attract the unattached (floating or indifferent customers). Hence, the body of unattached customers would be moving towards some firm depending on the marketing effort used [1618].

Only some part of the firms potential marketing ability may be in motion. The firm may still be able to inject some new brands or embark on an intensified advertising campaign or improve the quality of its product [1921]. Hence, there are a number of impulses that can be applied to move the body of unattached customers towards the firms in question.

2. The Mathematical Relationship of Management Evaluation of Potential Capacity in Determining Market Share

The position of the body of unattached customers is determined by the magnitudes of a number of independent variables.

Let (𝑥,𝑦,𝑧) be these variables, where

(i)𝑥 is say, the firm’s level of advertising expenditure;(ii)𝑦 is the number of the firm’s brands;(iii)𝑧 is a some quality variable.

These three variables can be expressed in a specified number of independent variables 𝜃,Φ,Ψ,, whereby if 𝑡 is the time, then 𝑥=𝑓𝑡,𝜃,Φ,Ψ,,(2.1)𝑦=𝑓𝑡,𝜃,Φ,Ψ,,(2.2)𝑧=𝑓𝑡,𝜃,Φ,Ψ,.(2.3)

Equations (2.1)–(2.3) may explicitly contain 𝑡, but they must not contain derivatives of 𝜃,Φ,Ψ, or any other differential coefficients with respect to time 𝑡.

Now, the body of unattached customers (𝑚) at a certain speed may be expressed mathematically as 𝐹𝑡=𝑚𝑑𝜈,𝑑𝑡(2.4) where 𝑑𝑠=𝑣𝑑𝑡,(2.5)

𝜈 being the speed, which can be measured by changes in sales to unattached customers (𝑠) with respect to time: 𝜈=𝑑𝑠.𝑑𝑡(2.6)

It follows that 𝐹𝑡𝑑=𝑚𝑑𝑡𝑑𝑠𝑑𝑑𝑡=𝑚2𝑠𝑑𝑡2=𝑚𝑣𝑑𝑠.𝑑𝑡(2.7)

An increase in production speed with a reduction in relative sales prices will reduce the percentage of unattached customers.

Integrating from 𝐴1 where 𝑠=𝑠1 and 𝜈=𝜈1 to 𝐴2, where 𝑠=𝑠2 and 𝜈=𝜈2, we write S2S1𝐹𝑡𝑑𝑠=𝑚,𝜈2𝜈11𝑑𝜈=2𝑚𝜈2212𝑚𝜈21.(2.8)

The left-hand side represents the effect 𝑈12 of the effort 𝐹, exerted on the attraction of unattached customers during the changes in market position from 𝐴1 to 𝐴2. The expression 1/2𝑚𝜈21 is defined here as the applied marketing effort and is denoted by 𝑇,1𝑇=2𝑚𝜈22.(2.9)

In an effort to maintain its market share, the firm’s effective marketing efforts match the competitors’ efforts.

Now, let 𝑉 be the firm’s marketing potentiality, where 𝑉 is a function of 𝜃,Φ,Ψ, and so on, we have 𝑚(𝑥𝛿𝑥+𝛿𝑦𝛿𝑦+𝑧𝛿𝑧)=𝑉,𝛿𝑉=𝜕𝑉𝜕𝜃𝛿𝜃+𝜕𝑉𝜕Φ𝛿Φ+𝜕𝑉𝜕Ψ𝛿Ψ+,𝛿𝑥=𝜕𝑥𝜕𝜃𝛿𝜃+𝜕𝑥𝜕Φ𝛿Φ+𝜕𝑥𝜕Ψ𝛿Ψ+,(2.10) and similar equations for 𝛿𝑦 and 𝛿𝑧.

Noting that 𝑚𝑥𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧=𝜕𝜃𝜕𝑉,𝑚𝑥𝜕𝜃(2.11)𝜕𝑥𝜕Φ+𝑦𝜕𝑦𝜕Φ+𝑧𝜕𝑧𝜕Φ=𝜕𝑉,𝑚𝑥𝜕Φ(2.12)𝜕𝑥𝜕Ψ+𝑦𝜕𝑦𝜕Ψ+𝑧𝜕𝑧𝜕Ψ=𝜕𝑉.𝜕Ψ(2.13)

If we now differentiate (2.1) we get 𝑥𝜕𝑥+𝜕𝑡𝜕𝑥𝜃𝜕𝜃+𝜕𝑥Φ𝜕Φ+𝜕𝑥Ψ𝜕Ψ+.(2.14)

Therefore, 𝜕𝑥𝜕𝜃=𝜕𝑥,𝑑𝜕𝜃(2.15)𝑑𝑡𝜕𝑥=𝜕𝜕𝜃2𝑥+𝜕𝜕𝜃𝜕𝑡2𝑥𝜕𝜃2𝜃+𝜕2𝑥Φ𝜕𝜃𝜕Φ+𝜕2𝑥Ψ𝜕𝜃𝜕Ψ=𝜕+𝜕𝜃𝜕𝑥+𝜕𝑡𝜕𝑥𝜃𝜕𝜃+𝜕𝑥Φ𝜕Φ+𝜕𝑥Ψ𝜕Ψ=+𝜕𝑥.𝜕𝜃(2.16)

Noting that 𝑥𝜕𝑥=𝑑𝜕𝜃𝑥𝑑𝑡𝜕𝑥𝜕𝜃𝑥𝑑𝑑𝑡𝜕𝑥=𝑑𝜕𝜃𝑥𝑑𝑡𝜕𝑥𝜕𝜃𝑥𝑑𝑑𝑡𝜕𝑥𝜕𝜃=𝑑𝑥𝑑𝑡𝜕𝑥𝜕𝜃𝑥𝜕𝑥𝜕𝜃.(2.17)

Then, 𝑚𝑥𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧=𝑚𝑥𝜕𝜃𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃.(2.18)

From (2.11) and (2.15), 𝑑𝑚𝑥𝑑𝑡𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃𝑚𝑥𝑑𝑑𝑡𝜕𝑥𝜕𝜃+𝑦𝑑𝑑𝑡𝜕𝑦𝜕𝜃+𝑧𝑑𝑑𝑡𝜕𝑧𝜕𝜃=𝑑𝑚𝑥𝑑𝑡𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃𝑚𝑥𝑑𝑑𝑡𝜕𝑥𝜕𝜃+𝑦𝑑𝑑𝑡𝜕𝑦𝜕𝜃+𝑧𝑑𝑑𝑡𝜕𝑧=𝑑𝜕𝜃𝑚𝑥𝑑𝑡𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃𝑚𝑥𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃=𝜕𝑉.𝜕𝜃(2.19)

In virtue of (2.9), we have 𝜕𝑇=𝜕𝜃𝑚[𝑥2+𝑦2+𝑧2].(2.20)

Therefore, 𝜕𝑇=𝜕𝜃𝑚[𝑥𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃],𝜕𝑇=𝜕𝜃𝑚[𝑥𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃].(2.21)

Hence, from (2.19), (2.21), we obtain 𝑑𝑑𝑡𝜕𝑇𝜕𝜃𝜕𝑇𝜕𝜃=𝜕𝑉.𝜕𝜃(2.22)

Similarly, 𝑑𝑑𝑡𝜕𝑇𝜕Φ𝜕𝑇𝜕Φ=𝜕𝑉,𝑑𝜕Φ𝑑𝑡𝜕𝑇𝜕Ψ𝜕𝑇𝜕Ψ=𝜕𝑉.𝜕Ψ(2.23)

Equations (2.22), (2.23) express the relationship between potential marketing ability and applied effort affecting the firm’s market share as determined by sales to unattached customers. The same relationship can be investigated when a number of simultaneous impulses (e.g., embarking on new advertising campaign, injecting of new brands, and introducing a substantial change in the quality of the product) are applied by the firm to its marketing efforts.

The sum of the virtual moments of the components of changes in sales to unattached customers would be equal to 𝑚[𝑥1𝑥0]𝛿𝑥+[𝑦1𝑦0]𝛿𝑦+[𝑧1𝑧0]𝛿𝑧.(2.24) We have 𝜕𝑇𝜕𝜃=𝑚𝑥𝜕𝑥𝜕𝜃+𝑦𝜕𝑦𝜕𝜃+𝑧𝜕𝑧𝜕𝜃.(2.25)

Let 𝑇0 and 𝑇1 be values of 𝑇 just before and just after the impulses. Then, 2𝑇0=𝑚[𝑥20+𝑦20+𝑧20],𝜕𝑇𝜕𝜃=𝑚𝑥𝜕𝑥𝜕𝜃0+𝑦𝜕𝑦𝜕𝜃0+𝑧𝜕𝑧𝜕𝜃0.(2.26)

Now, 𝑚[𝑥0𝛿𝑥+𝑦0𝛿𝑦+𝑧0=𝑚𝑥𝛿𝑧]0𝜕𝑥𝜕𝜃0+𝑦0𝜕𝑦𝜕𝜃0+𝑧0𝜕𝑧𝜕𝜃0𝑥𝛿𝜃+0𝜕𝑥𝜕Φ0+𝑦0𝜕𝑦𝜕Φ0+𝑧0𝜕𝑧𝜕Φ0+𝑥𝛿Φ0𝜕𝑥𝜕Ψ0+𝑦0𝜕𝑦𝜕Ψ0+𝑧0𝜕𝑧𝜕Ψ0.𝛿Ψ(2.27)

By referring to (2.15), it can be readily shown that 𝜕𝑥𝜕𝜃0=𝜕𝑥𝜕𝜃0,andsoon.(2.28)

Therefore, 𝜕𝑇𝜕𝜃0=𝑚𝑥0𝜕𝑥𝜕𝜃0+𝑦0𝜕𝑦𝜕𝜃0+𝑧0𝜕𝑧𝜕𝜃0.(2.29)

There will also be similar expression for 𝜕𝑇𝜕Φ0=𝜕𝑇𝜕Ψ0,andsoon.(2.30)


Similarly, it can be shown that 𝑚[𝑥0𝛿𝑥+𝑦0𝛿𝑦+𝑧0𝛿𝑧]=𝜕𝑇𝜕𝜃1𝛿𝜃+𝜕𝑇𝜕Φ10𝛿Φ+𝜕𝑇𝜕Ψ10𝛿Ψ+.(2.32)

From (2.24), (2.31), and (2.32), 𝑚[𝑥1𝑥0]𝛿𝑥+[𝑦1𝑦0]𝛿𝑦+[𝑧1𝑧0=]𝛿𝑧𝜕𝑇1𝜕𝜃1𝜕𝑇0𝜕𝜃0𝛿𝜃+𝜕𝑇1𝜕Φ1𝜕𝑇0𝜕Φ0𝛿Φ+𝜕𝑇1𝜕Ψ1𝜕𝑇0𝜕Ψ0𝛿Ψ+.(2.33)

Let 𝜕𝑇1𝜕𝜃1𝜕𝑇0𝜕𝜃0𝛿𝜃=𝜕𝑇𝜕Φ120.(2.34)

If 𝑋,𝑌, and 𝑍 are the components of the applied impulse at (𝑥,𝑦,𝑧) then (𝑋𝛿𝑥+𝑌𝛿𝑦+𝑍𝛿𝑧)=𝑃𝛿𝜃+𝑄𝛿Φ+𝑅𝛿Ψ.(2.35)

Therefore, 𝜕𝑇𝜕𝜃1𝜕𝑇𝜕𝜃0=𝜕𝑇𝜕𝜃10=𝑃,𝜕𝑇𝜕Φ1𝜕𝑇𝜕Φ0=𝜕𝑇𝜕Φ10=𝑄,𝜕𝑇𝜕Ψ1𝜕𝑇𝜕Ψ0=𝜕𝑇𝜕Ψ10=𝑅.(2.36)

𝑃,𝑄, and 𝑅 are called the generalized components of marketing impulse, while (𝜕𝑇/𝜕𝜃)/𝛿𝜃 is called generalized component of marketing effort.

3. Conclusions

This paper has devised a method by which a particular firm can evaluate its potential capacity in determining its market share.

The relationship between the applied marketing effort and the potential ability of the firm determining its market share has also been demonstrated.

The paper also investigated the effect of a number of simultaneous marketing impulses on the movement of body of unattached customers and hence the size of the market shares.


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