What can we learn from ancient sales ledgers?

Victorian era customer purchase records from a London tailor reveal a close fit between actual and predicted buying using the stochastic NBD model. Within this conceptual framework, novel data generates useful results, in this case showing that the buying patterns of high-end customers in the 19th century are familiar and comparable to 21st century counterparts. This is useful in categories that lack longitudinal data, such as many luxury goods. The first contribution of this research is to show that luxury goods consumer culture is steady over time. Second, the NBD model can be used to predict market penetration growth. Third, the results indicate that marketers should seek to increase the total number of customers rather than just focus on heavy ones and finally the NBD model can serve as a benchmark tool to evaluate any real change in buying behavior (as opposed to stochastic change), caused by marketing activities.