One pitfall I experienced in commercial radio was leveling with listeners by telling them that we couldn't play requests. It was especially awkward to tell listeners this when their requests were in the rotation and hadn't been played recently. In one case, I remember telling a caller that we were required to follow the playlist, but his requested song was scheduled to come up in 12 hours.
I could just imagine a station bumper between songs promising "your favorite music--within a half-day of your craving for it."
