A key performance indicator (KPI) is a marketing metric that reflects what is important to the organization and is used to monitor the health performance of a business, brand or service.
Typically, these are metrics that can signal deviations from trends, past performance, or expected values and are used to assess reflect the progress that the entity is making toward objectives.
Often KPIs are selected for display on the organization’s dashboards. 
- ^ Common Language Project Team. November 2016.