It's not as cut and dry as that, apparently. From that BusinessWeek article:

Washington State’s health agency sold its database 95 times that year, collecting a mere $15,950. Donn Moyer, a spokesman for the state’s health department, says it chose to release extra identifying information such as patients’ Zip Codes to make its data more useful.

The Harvard researcher's point is that it's possible to identify individuals in the datasets being sold in some scenarios.