The Floof-O-Meter is a count of how many times someone has "nuzzled you" by pressing the "nuzzle" button next to someone's username. If someone "nuzzles" you (or "floofs) it means that they are rewarding you for kind, helpful, or a good kind of behavior towards the community. Receiving a floof is not too common, but it means that you were rewarded for showing good behavior. In other words, it is something well-earned.