In the hayday of top 40 call letters were king. For those of you too young to remember radio stations in the U.S. are given call sign or letters to identify themselves. In the U.S. east of the Mississippi got a call sign that started with "W" and West of the Mississippi, the F.C.C. assigned a "K". A few exceptions exist. Stations like KDKA in Pittsburg and WOAI in San Antonio got their call letters before this geographic line was drawn.
Top 40 stations quickly learned good call letters helped in the ratings race. Stations were looking for call letters that spelled something like WAKY (one of my favorites).
Right behind the call letters the frequency with a rhyme helped, i.e. "the mighty ten ninety".
Most later day programmers think the only thing that is important is a clever name for their station that has nothing to do with either the call letters or the frequency. "Big Dog" has now given away to "Alice".
Do the rating services offer listings now for XM or Sirius? Or even car CDs, Ipods and the like. I just bought a new car radio that plays, SD cards, USB flash drives, an upfront plug for Ipods and the like. If offers highway broadcast info, FM and maybe AM even though I haven't tried it yet. Haven't got past the SD card which also displays on a flashy screen the artist, song title and any other info.and some flashing spectrum lights.