Return on Ad Spend (ROAS) measures how much revenue is generated for every rupee/dollar spent on ads — a ROAS of 3 means ₹3 earned for every ₹1 spent. This lesson covers how to calculate and interpret ROAS, along with connecting ad performance to broader business metrics like Customer Acquisition Cost (CAC) and Lifetime Value (LTV), helping you judge whether a campaign is actually profitable, not just generating clicks or leads.