Calculating consumer turnover is more difficult than it appears: Can free trial users be included? Contracts on a month-to-month basis? Should it just separate customers who are about to renew their contracts? As a result, SaaS companies differ greatly in how they react to a seemingly simple question like, "How many of your customers did not renew in a given period of time?"
Since there are hundreds of competing churn models, what matters more than the formula(s) an organization prefers is that it regularly benchmarks itself. Churn is an ephemeral KPI. Seasonality, product shifts, competitive conditions, pricing expectations, customer support, and even public relations incidents may all have an effect. Changing one's churn measurement on a regular basis will make it more difficult to understand what is causing a company to lose customers and make improvements to its business, which is ultimately why the metric is tracked in the first place.
