At which point, it became obvious that more specific information must be provided, to accurately understand the various demographics of listeners. This would lead to the development of the PPM, as it would become a way of blending the advances in technology, with changes in the underlying tastes and choices of listeners. Where, they would no longer rely on someone keeping a diary over a seven day time period (under the Dairy system). Instead, this would tell researchers what stations each listener would listen to based upon, the sounds the device was recording. This would eliminate a certain amount of bias that occurs, when someone is keeping a diary. At the same time, this technology provides information to researchers in real time. As a result, a variety of stations and radio networks have begun to use the device in large urban markets, as a way to be able to more accurately determine listener choices. Evidence of this can be seen by looking no further than with: CBS, the Beasely Broadcasting Group and the Spanish Broadcasting system. Where, all three major networks are using the device in every major urban market. This is because the PPM is effective, at identifying changes in the buying relationship of consumers. For advertisers, this is important because, this relationship can change rather quickly (in urban markets). However, in rural markets the technology would not work as effectively, because businesses purchase advertising based on a face-to-face relationship with executives. This makes using the technology in these markets, too expensive and inaccurate. The information from...

Where, it can predict changes in the basic buying relationship of listeners. Yet, because the technology has been shown to be expensive and inaccurate in rural markets; means that there could be some validity to the points made by critics. As a result, one could use this information to establish a basic foundation, as to the possible strengths and weaknesses of using this technology in various radio markets.
Moreover, Warren (2004) discusses how the PPM has been touted as an accurate technology to understand various listener preferences in real time. However, the author believes that the device will record the sounds of what is being heard, not the actual content that the listener is choosing. This is problematic because, it can cause radio stations to assume that someone prefers a particular broadcaster, when it could be background noise. For example, someone utilizing the PPM, could record a number of different stations when they go about their daily tasks. Where, they may hear Spanish music in a store, classical music in the car and elevator music in an office building. The device would record these sounds as actual listener preferences, even though the person is not choosing to listen to a particular genre of music. This can provide radio stations, with inaccurate information about what choices listeners are preferring. According the author, this fundamental difference in the way information is reported, will always