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That's not great for the Apple Watch. If they sell a device purely for sleep tracking, why would they implement an app on the Apple Watch?
 
I have terrible sleep habits and so it is obvious. I'm regularly tired/exhausted. As posted earlier, it has become my norm. While I don't think such a device will help my individual situation, it may. The power in the empirical data lies in finding patterns that are not obvious. I feel pretty certain that new insights can be gained from this kind of device.
I don't even think it's obvious. I have good sleeping habits but I regularly feel tired and exhausted too. Doctors have found nothing in my blood or diet to explain this. My point is that without regular scientific metrics that can even form or suggest a pattern, nothing can or should be assumed. We are looking for data so imagine how many people will benefit from sleep tracking who are not necessarily looking for the data.
 
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