Measuring marketing success involves tracking various Key Performance Indicators (KPIs) such as website traffic, conversion rates, customer acquisition costs, and return on investment (ROI). Tools like Google Analytics, social media insights, and CRM software can provide valuable data on campaign performance. By analyzing these metrics, businesses can identify what’s working, what’s not, and make data-driven decisions to optimize their marketing efforts. Regularly reviewing and adjusting strategies based on performance data ensures continual improvement and better results.