Return on ad spend (ROAS) is a crucial metric in marketing and advertising that measures the revenue generated for every dollar spent on advertising, applicable across various industries. The formula for calculating ROAS is straightforward: total revenue generated divided by the amount spent on a campaign. This metric helps businesses assess the effectiveness of their advertising efforts by comparing returns from multiple campaigns, thereby informing future ad spending and strategy decisions. While ROAS focuses on revenue from ads, return on investment (ROI) is a broader profitability measure that includes all costs, such as overheads and payroll. A good ROAS is subjective and varies based on factors like a company's operating costs and profit margins, with a 4:1 ratio often cited as a common benchmark for established businesses, though startups may have different expectations due to their financial dynamics.