A KPI (Key Performance Indicator) is the core number that measures how close you are to a goal. In marketing and sales it focuses the team's attention on what matters: MQL count, conversion, CAC, closed deals.
The wrong KPI is dangerous: if you make "number of calls" the KPI, the team makes many calls but sales don't grow. The right KPI ties to a result (sales, MQLs), not to "activity."
