Measuring the success of marketing campaigns requires a focus on several key metrics, including return on investment (ROI), conversion rate, customer acquisition cost (CAC), and customer lifetime value (CLV). ROI helps assess the profitability of the campaign relative to its costs, while conversion rate gauges the effectiveness of the campaign in turning prospects into customers. CAC indicates the average cost incurred to acquire a new customer, providing insight into spending efficiency, whereas CLV estimates the total revenue a customer generates during their relationship with the brand, informing long-term strategy.