Some people wear their hearts on their sleeves. Others, meanwhile, measure their heartrate on their wrists. The latter group is growing exponentially, ushering in a multi-billion-dollar wearables market, from watches that count steps and heartbeats to ear buds that monitor a woman’s body temperature to calculate the ideal time to procreate.
Probably one of the most successful and well-known brands, Fitbit, sold more than 21 million products in 2015, according to a wearables market analysis... read more