It is most appropriate to measure spending per customer as a proportion of profitability during...

Customer Acquisition: This is the process of gaining new customers or clients for a business. It involves marketing and sales strategies aimed at bringing new customers into the company’s fold.

Spending per Customer: During the customer acquisition phase, companies typically invest heavily in marketing, promotions, and discounts to attract new customers.

Profitability Consideration: Measuring spending per customer in this phase helps companies understand the cost-effectiveness of their acquisition strategies and determine the return on investment.

Rationale: High spending is expected in customer acquisition because it is a critical phase for building a customer base. This metric helps in evaluating and optimizing acquisition strategies to ensure long-term profitability.

References:

Kotler, P., & Keller, K. L. (2016). Marketing Management. Pearson.

Kumar, V., & Shah, D. (2004). Building and Sustaining Profitable Customer Loyalty for the 21st Century. Journal of Retailing, 80(4), 317-329.