There are two other terms which you might see used, which are the counterparts to churn:
CRR (Customer Retention Rate) which is equal to 1 – Customer Churn Rate
DRR (Dollar Retention Rate) which is equal to 1 – Dollar Churn Rate
So a business that has a negative churn rate, will have a Dollar Retention Rate of greater than 100%. These are some of the very best SaaS business out there. Examples of DRR greater than 100% include: Zendesk: 123%, NewRelic 115%, Box: 130%, Rally Software 127%.