This document discusses measuring the return on investment (ROI) of social media marketing. It emphasizes that social media requires resources like people, technology, and time to implement successfully. It then outlines a process for proving the business value of social media through a proof of concept that isolates patterns and quantifies changes in key metrics like sales, transactions, and customers. By linking social media activities to changes in these metrics over time, the ROI can be calculated by determining the revenue gains and cost savings. This process helps justify continuing to allocate resources to social media marketing.