Knowledge of marketing theories, such as the Double Jeopardy Law (and others discussed throughout this book) are useful in creating premises for arguments supporting marketing strategies.
In the Appeal to Possibility discussion, Jacqueline and Conner ponder how to increase their shampoo brand’s market share. They know that market share, over a given period of time, is a function of the number of customers who purchase a brand (i.e., market penetration) and the frequency of brand purchase. They want to increase their brand’s share and, to achieve that goal, believe it will be easier to increase the brand’s purchase frequency than the number of consumers who will purchase it. Their Appeal to Possibility, Appeal to Ignorance, and a misunderstanding of how market penetration and purchase frequency are related have led them to a bad conclusion.
If they had been aware of the Double Jeopardy Law, Jacqueline and Conner could have made a better argument supporting a different brand growth strategy. The Double Jeopardy Law states that
smaller market share brands are penalized twice; not only have they fewer customers who buy them (their penetration is smaller than that of big brands), but also customers who do buy them do so less often—and, in memory metrics, less popular brands are known by fewer people and those people are slightly less likely to say that they like it.1
Based on analysis from the Ehrenberg-Bass Institute,2 in many situations, the key to increasing market share is to increase penetration, not to increase purchase frequency among those currently purchasing the product. Had Jacqueline and Conner been aware of this law, they could have reframed their suggested strategy to increase market share by focusing on increasing the brand’s penetration, not the brand’s purchase frequency among current customers.
Table 6.1 Market share, market penetration, and purchase frequency across selected shampoo brands3
Shampoo brands |
Market share (%) |
Annual market penetration (%) |
Purchase frequency(average) |
Head & Shoulders |
11 |
13 |
2.3 |
Pantene |
9 |
11 |
2.3 |
Herbal Essences |
5 |
8 |
1.8 |
L’Oreal Elvive |
5 |
8 |
1.9 |
ove |
5 |
9 |
1.6 |
Sunsilk |
5 |
8 |
1.7 |
Vosene |
2 |
3 |
1.7 |
Researchers have observed the Double Jeopardy Law across a variety of industries such as consumer packaged goods (e.g., what you find in the grocery store), durable goods (e.g., vehicles and electronics products), and services. Table 6.1 shows how market share, annual market penetration, and purchase frequency compare for selected shampoo brands.
Note that all three columns of figures are highly correlated. The theory and empirical evidence suggest that market penetration drives market share and purchase frequency. But if one is not aware of the Double Jeopardy Law, one might attempt to develop a marketing strategy that seeks to increase market share by increasing purchase frequency, which is highly unlikely to be effective.
Byron Sharp discusses 11 marketing laws in his book How Brands Grow. You should be familiar with them, as well as with the Journal of Empirical Generalizations in Marketing Science at //empgens.com/ ArticlesHome/Articles.html
Remember: Some marketing strategies not only don’t work. They can’t work. It’s the law!