One thing I appreciated about taking listeners' song requests on the radio: The listeners and I both understood that there was a grace period. They knew that other people called in, as well, and that they wouldn't likely hear their requests immediately. Once, when I played a request about one minute after a listener called in, he called back and said, "Thanks for playing that song. I'm impressed that you got it on the air so quickly." I replied, "It segued well with the song I was playing, so I ran to the music library and cued the song up as fast as I could."
Song requests: Now and then, they augment your radio show and keep the listeners tuned in.