Sales by Multi-Product Retailers: A Comment

Immanent to the retail business is its multiproduct nature. In a recent issue of this journal Richards (2006) introduces a multiproduct model for perishable food items. Richards concludes that depth and breadth of sales are complementary marketing tools to increase store sales. He also provides empirical support for this hypothesis. We will show in the following that Richards' model does not suggest a complementarity between depth and breadth of sales. Instead, these tools are substitutes in his model. Therefore, the interpretation of his empirical result has to be reconsidered. Copyright (C) 2009 John Wiley & Sons, Ltd.