In the fall of 1998, The Arbitron Company and Continental Research (Arbitron's subsidiary in the United Kingdom) conducted a pilot test of the personal portable meter (PPM) in Manchester, England.
Arbitron's U.S. trial of its Portable People Meter (PPM) system has added the 189 Houston-area stores of that country's largest drugstore chain, Walgreens. To take part, the stores will use encoded ...