The Apple watch will help in gathering personal data of the medical kind as will all wearable devices. This will be of use to big pharma, doctors, insurance companies and the like. The Apple watch has the added advantage of being around on an individual more of the time than any other Apple device. You are bound to forget your mobile at times, but the watch, never. Its absence is more acutely felt as it is discernible to the user both by touch and sight.