Advertising agencies track the ROI of traditional ads using various methods. They set clear objectives before launching campaigns. Surveys and customer feedback help gauge ad effectiveness. Tracking sales data before and after campaigns shows direct impact. Agencies often use unique phone numbers or promo codes to measure responses. They analyze website traffic to see if ads drive online visits. Media impressions and reach metrics provide insights into audience exposure. Comparing costs to generated revenue calculates the ROI. Agencies also conduct market research to assess brand awareness changes. These methods help agencies evaluate the success of traditional advertising efforts.