Moshe Givon

Assessing the relationship between the user-based market share and unit sales-based market share for pirated software brands in competitive markets

Abstract This article argues that in a competitive software market, in the presence of differential piracy and brand switching among the various brands within a software product category (e.g., spreadsheets), there may be no relationship between market estimates based on unit sales and the user base of a software brand (e.g., Lotus 1-2-3). Hence, marketing strategies developed for the software brand based on unit sales-based market share may be misleading. To support our argument and to quantify the relationship between unit sales-based market share and the user-based market share, we first extend a diffusion modeling approach for pirated software product categories to model the legal and illegal adoption dynamics of a software brand within a software product category. Second, to examine empirically the relationship between the user-based market share and the unit sales-based market share for a brand, we consider the diffusion of the major brands of two types of software product categories, spreadsheets and word processors, in the United Kingdom. Results indicate that in the product category of spreadsheets, for Lotus 1-2-3, the user-based market share was always less than the unit sales-based market share. On the other hand, in the product category of word processing software, the user-based market share for WordPerfect was always greater than the unit sales-based market share. Marketing implications of these results for Lotus spreadsheets, Novell WordPerfect, and the software industry are discussed.

Variety seeking, market partitioning and segmentation

Abstract This paper ties together hierarchical partitioning of product markets, segmentation and variety seeking. Individual variety seeking is shown to be a more meaningful partitioning criterion than simple aggregate brand switching. Variety seeking is attribute dependent and thus should not be directly related to the consumers socio-economic and demographic characteristics. Alternatively, the consumers way of partitioning the market is suggested as a useful criterion for segmentation.

Homogeneity and heterogeneity in stochastic models of brand choice behavior

Abstract Heterogeneity of consumers is one of the cornerstones of empirical findings and theories in marketing. It serves, for example, as the foundation for such areas as market segmentation and product differentiation. This paper attempts to trace and clarify the evolution over the last twenty years of the homogeneity assumptions in the area of stochastic models of brand choice behavior. In analyzing individual choice behavior by means of stochastic models, all individuals were often assumed to possess the same set of transition probabilities or follow the same stochastic process. However, empirical studies at the individual level indicate that individuals are actually non-homogeneous in those probabilities and processes. In this article we provide an analytical proof that if the behavior of individuals is specified to be homogeneous when it is not, wrong inferences about the type of stochastic process individuals follow and about the expected behavior of the total population will be drawn. Ways to remedy these problems by allowing for heterogeneity are reviewed. The implications of heterogeneity and our findings in the various application areas which utilize stochastic choice models are examined.

Intertemporal aggregation of heterogeneous consumers

Abstract This paper deals with a relatively unexamined facet of stochastic brand switching models — their connection to market share models. We derive a composite market share model based on aggregation of heterogeneous Markovian type individuals each purchasing a brand from the product class several times during the period of analysis. The characteristics of this composite model are examined and interestingly suggest a Markov type market share model. Moreover, this examination sheds some light on a phenomenon uncovered in econometric studies of market share response to advertising - the slow decay of the lagged market share term as the length of the measurement period is increased.

Partial carryover of advertising

A model that combines advertising carryover with purchase reinforcement is presented. It accommodates the possibility that certain members of the consumer population rely only on their experience with the product, while others are also affected by past advertising. Empirical results with two product categories indicate that for bimonthly data advertising retention does not exist at all.