This rotated, but otherwise unretouched screen capture from StreamingRadioGuide.com shows the actual, calculated listenership for Rush Limbaugh, with the oldest dates on the left.
![](http://i920.photobucket.com/albums/ad50/richardtmyers/rushchart.jpg)
Popularity Trend graph for Rush Limbaugh
The Portable People Meter is "...worn like a pager, and detects hidden audio tones within a station or network's audio stream, logging each time it finds such a signal. It has proved to be much more accurate than the old handwritten logs or wired meters, and is immune to forgetful test subjects."
Portable People Meter, Wikipedia
Please note: this diary contained errors. For a more recent evaluation, please see:
http://www.dailykos.com/...