Campaign A: Quantity mailed was 1.3 million pieces and the response rate was 1.8%. Campaign B: Quantity mailed was 800,000 pieces and resulted in the acquisition of 10,000 customers.

(a) Which campaign had the best response rate? (b) If the CPM of the first campaign was $800 and the second was $900, which campaign had the lowest cost per acquisition? (c) Which campaign was better, A or B? Please explain your reasoning.