A Key Performance Indicator (KPI) is an indicator of a critical performance point. In marketing, KPIs can be statistics and figures from marketing campaigns, such as click-through rates, engagement rates and traffic to your website.
KPIs can be utilised to optimise your future strategy; showing you what was most and least effective in previous campaigns. By using KPIs as a guide for future campaigns, marketers are always evolving and improving.
The data for KPIs is available to anybody running marketing campaigns, but it takes a degree of expertise to interpret them correctly.