Wearing a fitness tracking device could earn you cash from your health insurance company. At first, this sounds lucrative for the people who participate, and good for the companies, who want healthier insurance customers. But it's not quite so simple.

Under the program, people who have certain health insurance coverage plans with UnitedHealthcare can elect to wear a Fitbit activity tracker and share their data with the insurance company. The data would be analyzed by Qualcomm Life, a company that processes medical data from wireless sensors for doctors, hospitals and insurance companies. Depending on how active participants are, as measured by the Fitbit, they could earn as much as US$1,500 toward health care services each year.