In my experience, when the numbers go up, people think the improvement was caused by their actions, by whatever they were working on at the time. That is why it’s so common to have a meeting in which marketing thinks the numbers went up because of a new PR or marketing effort and engineering thinks the better numbers are the result of the new features it added. Finding out what is actually going on is extremely costly, and so most managers simply move on, doing the best they can to form their own judgment on the basis of their experience and the collective intelligence in the room.
