The original article seems to be saying that the carriers track and sell phone location by cell triangulation ("less accurate than using GPS, but cell tower data won't drain a phone battery"). This is less accurate, as seen by the example of "within a city block."

The parent comment seems to be saying that the OS and apps use the internal GPS data to get a much more accurate location, which is then freely transmitted somehow and shared and sold. My question is to clarify that this more accurate data, needed to enable the "walk into specific store" scenario, can only be obtained via data (eg 3G, LTE, or wifi)?

Therefore not buying a data plan or turning off cellular data manually should prevent the GPS-accuracy tracking, but the only way to prevent the less accurate cell-tower tracking is to use a faraday cage.