In the Software as a Service (SaaS) industry, several key metrics should be tracked to assess the health and performance of the business. These include Monthly Recurring Revenue (MRR) to measure the recurring revenue generated from subscriptions, Customer Acquisition Cost (CAC) to understand the cost of acquiring new customers, Churn Rate to monitor the rate at which customers cancel their subscriptions, Customer Lifetime Value (CLTV) to assess the long-term value of a customer, Gross and Net Revenue Retention to track revenue retained from existing customers, and Average Revenue Per User (ARPU) to gauge the average revenue generated from each user. Additionally, monitoring metrics related to user engagement, product usage, and customer satisfaction can provide valuable insights for optimizing the SaaS business model and ensuring its growth and sustainability.