MER measures the ratio of revenue generated per dollar spent on marketing/advertising. It helps gauge the efficiency and return of your paid marketing investments.
Formula: MER = Total Revenue from Marketing Source / Total Marketing Spend
Example: If your Facebook ads generated $250,000 in revenue from a $50,000 ad spend, the MER would be 5 ($250,000 / $50,000 = 5). An MER above 1 means you're generating more revenue than you're spending.
