Double jeopardy (marketing)
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Double jeopardy is an empirical law in marketing where, with few exceptions, the lower-market-share brands in a market have both far fewer buyers in a time period and also lower brand loyalty.
The term was originally coined by social scientist William McPhee in 1963 who observed the phenomenon, first in awareness and liking scores for Hollywood actors, and later in behaviours (e.g. reading of comic strips and listening to radio presenters).[1]
Shortly afterwards, Andrew Ehrenberg discovered the double jeopardy law generalised to brand purchasing.[2] Subsequently, double jeopardy has been shown to apply across many categories of product.[3]
This empirical law-like phenomenon is due to a statistical selection effect that occurs if brands are broadly substitutable selling to much of the same types of people (often referred to as a lack of product differentiation and market partitioning). The double jeopardy empirical generalization is explained and predicted by the NBD-Dirichlet theory of repeat purchase.[4][5] See also Schmittlein, Bemmaor and Morrison (1985).[6]