Track and understand how customers use the product and the quanlity of features. Avoid feature creep and over complex product.
Monthly/daily unique visitors; Monthly/daily active users (MAU/DAU); Average session time.
User/customer conversion rate; Monthly/daily retention rate; User sentiment/net promoter score (NPS).
Average revenue per user (ARPU); User/customer acquisition cost (UAC/CAC); User/customer lifetime value (ULV/CLV).