Gross Profit and Net Profit are fundamental to calculating ROI. Gross Profit is the revenue generated from sales minus the cost of goods sold, while Net Profit is what's left after all expenses are deducted. Understanding these profits helps in accurately determining the return part of the ROI equation.

Break-Even Analysis and Payback Period are closely related to ROI as they also help in evaluating the viability of an investment. Break-Even Analysis determines when an investment will start generating profit, and the Payback Period measures how long it will take to recoup the initial investment. These metrics complement ROI by providing additional dimensions of financial performance.

Campaign Performance Metrics and Outcome Metrics are essential in marketing to measure the effectiveness of campaigns relative to their costs. Similarly, Customer Acquisition Cost (CAC) and Cost Per Acquisition (CPA) are critical in understanding how much it costs to acquire a new customer. These metrics are integral to calculating the ROI of marketing efforts.

Case Studies and ROI Analysis are tools used to understand past investment performances and predict future outcomes. Performance Tracking helps in continuously monitoring the ROI, ensuring that investments are on track to meet their expected returns. Economic Feasibility and Cost Optimization are broader concepts that encompass ROI to ensure that investments are financially sound and efficient.

Financial Metrics and Cost-Benefit Analysis provide a comprehensive evaluation of investments. While ROI focuses on profitability, these metrics offer a broader view of financial health and efficiency. Performance Metrics, in general, are vital for assessing the success of any investment, ensuring that all aspects of performance are considered in decision-making.