Attrition is the loss of users from your product or service. For SaaS or enterprise software, this may be measured through licence cancellations. For other models, it may simply be measured when someone stops using the product or their account is deactivated.
Measuring attrition is a key product strength indicator. It can indicate if users are gaining lasting value from your product.
When looking at attrition, cohort analysis can be useful to identify any patterns or underlying reasons behind cancellations. Are users cancelling from a similar background, did they sign up at a similar time?