• Customer retention rate = The percentage of customers who stay with you over the total number of customers.  The downside is that this number ignores the fact that some customers are more important/valuable than others.
• Revenue retention rate = Percentage of total potential revenue retained.  This metric misses the impact of account expansion but works better in environments with predictable customer contracts.
• Average customer revenue (revenue yield) = total revenue divided by the number of customers.  This  gives you a sense of how well you are growing your wallet share with customers.
• Repeat purchase rate: As the name implies, this reflects the percentage of business from existing customers.
• Net promoter score: The industry standard metric captures how likely a customer is to tell a friend about your business.

I’ve seen a range of approaches and find that more than one metric is often needed to tell the whole story.

Did I miss any other meaningful retention metrics?