The Cosmetric in question is that “the Tavis Smiley Show had a 29 percent African American audience, highest of any show on the NPR network.” Sounds impressive, doesn’t it? But it is a big number because the Tavis Smiley Show wasn’t on as many stations as most NPR shows.
Tavis Smiley was on 83 NPR stations. Had the program been on the same number of stations as Fresh Air (458 stations) or Talk of the Nation (244), the percentage of African American listeners would have gone down sharply. That's because the Tavis Smiley show was initially marketed to and cleared by stations that target African American audiences. The stations that had not yet cleared the show had far fewer African Americans to contribute to the Tavis Smiley national audience. So getting more stations (a good thing) would have reduced the percentage of African Americans listening; making it look like the program was attracting fewer African Americans even when the number of African American listeners would have gone up.
The lesson here is that percentages are never good measures of success because they can change for the wrong reasons. Real numbers of people listening, not percentages, are the true measure of success. The first step to improving public radio’s public service is focusing on the metrics that matter. That’s the subject of a future entry. In the meantime, we'd make our lives easier by not covering up reality with a thick layer of Cosmetrics.