Macroscopic quantum measurements: In what direction does a magnet point?

We introduce the concept of macroscopic quantum measurement, that is, a quantum formalism describing the measurements we perform continuously in our everyday life; for example, when looking at a magnet. We idealize the problem by considering parallel spins whose direction has to be estimated. We present a physical measurement model weak enough to almost not disturb the quantum state, but strong enough to provide almost the maximal amount of information in a single shot. Interestingly an intermediate coupling strength between spin system and measurement apparatus achieves better results than a strong coupling.