The document discusses how to measure the return on investment (ROI) of social media marketing. It outlines different metrics that accountants and marketers use to measure performance. These include numbers of customers, transactions, and revenue for accountants, and website traffic, social mentions, and fan growth for marketers. The document recommends tracking these metrics over time both before and after social media campaigns, and looking for connections between increases in social media metrics and increases in business metrics like sales and transactions. It provides examples of free and paid tools to track social media metrics and discusses how to calculate ROI by comparing changes in revenue to the costs of social media activities.