Measuring the impact of promotions on category performance can be done in various ways, such as pre-post analysis, market response modeling, test and learn, and customer analytics. Pre-post analysis involves comparing the sales and profit of the promoted product or category before and after the promotion period, utilizing historical data or a control group. Market response modeling applies statistical techniques to estimate the causal relationship between promotions and sales, while controlling for seasonality, competition, and consumer behavior. Test and learn involves running experiments with different promotion types, levels, or formats to measure the results using a randomized or matched design. Lastly, customer analytics use customer data such as loyalty cards, surveys, or online behavior to segment, target, and personalize promotions as well as to evaluate their impact on customer satisfaction, loyalty, and lifetime value.