This article wasn't what I thought it was going to be -- but at the time of year that we're creating our metrics for next year, it rang true. So often we create dubious numbers, instead of focusing on measuring if we're meeting a need, and encouraging people to come back.
This part in particular resonated: "But whatever it is, it should be a signal that they are using their product in the way you expected and that they use it enough so that you believe they will come back to use it more and more."