"Here are some rules of thumb for what makes a good metric—a number that will drive the changes you’re looking for.
A good metric is comparative. Being able to compare a metric to other time periods, groups of users, or competitors helps you understand which way things are moving. “Increased conversion from last week” is more meaningful than “2% conversion.”
A good metric is understandable. If people can’t remember it and discuss it, it’s much harder to turn a change in the data into a change in the culture.
A good metric is a ratio or a rate. Accountants and financial analysts have several ratios they look at to understand, at a glance, the fundamental health of a company. You need some, too.
A good metric changes the way you behave. This is by far the most important criterion for a metric: what will you do differently based on changes in the metric?"
Trechos retirados de "What Makes a Good Metric?"