Tracking key metrics is essential for measuring and driving SaaS growth. First, monitor your Customer Acquisition Cost (CAC) to ensure that your marketing and sales efforts are cost-effective. Monthly Recurring Revenue (MRR) and Annual Recurring Revenue (ARR) are crucial for understanding your revenue growth. Churn rate indicates customer retention and can help you identify potential issues early. Additionally, track customer lifetime value (CLV) to assess the profitability of your customers over time. Finally, monitor engagement metrics such as user activity, login frequency, and feature usage to understand how customers are interacting with your product.