A KPI stands for Key Performance Indicator.   KPIs are business and marketing measurements to help you determine how effective your business is.  They may be high-level or low-level.

A KPI needs to take into account a desired outcome, how to measure progress, how to influence the outcome and when you will review the progress.

Some marketing carpet business KPIs are web traffic sources, website total visitors, click through rate, new leads generated and lead conversion rate.