With all the money in the commercial world hanging on the results, TV ratings folks are constantly reinventing the way they measure ratings, and updating the demographics numbers for various networks, stations, and individual shows. And yet, radio, which relies at least as much on advertising revenue as television, has a laughably ineffective method of measuring audience share and ratings. The Arbitron company, which collects radio listenership data, “has long been under siege from its clients — radio stations — for this extraordinarily funky system, which is often blamed for wild spikes up and down in a station’s ratings.”