Measuring CRM systems in B2C marketing primarily focuses on understanding customer behavior and loyalty. Key metrics include the Customer Retention Rate, which tracks how many customers continue engaging over time, and Customer Lifetime Value (CLV), predicting the total revenue a customer will generate. Another crucial aspect is analyzing the Customer Acquisition Cost (CAC) to understand the efficiency of new customer outreach, alongside the Churn Rate, indicating customer attrition. Furthermore, CRM systems evaluate Customer Satisfaction (CSAT) and Net Promoter Score (NPS) to gauge sentiment, alongside various Engagement Metrics like email open rates and website interactions. Ultimately, success is also measured by Conversion Rates across different marketing campaigns, ensuring effective customer journey optimization and driving repeat purchases.