Eric RiesThe Lean Startup, 2011
Numbers that look impressive but don't inform decisions — cumulative totals and raw traffic — versus actionable metrics that establish cause and effect per cohort.
Alistair Croll & Benjamin YoskovitzLean Analytics, 2013
A good metric is comparative, understandable, a ratio or rate, and changes behaviour — if a number won't change what you do, stop reporting it.
The EclipseFrontiers® LensIf a number can't change a decision, it's decoration.