Radio listening as cultural anthropology

So every morning, I listen to a bunch of different stations on the way to work, mostly looking for a song, not a shock jock, but occasionally I hear a little snippet of morning program. One curiousity of these programs is the WHUR morning show (96.3), which is an acutal local morning show, from a DC station that plays "adult" (in the "adult contemporary" sense) R&B. There's a daily feature they have called "the D.C. thrusts". This guy starts rhyming (poorly) about said thrusts, ( You must......you must trust.........you must trust that thrust....), and then he gives a list of names of people who have birthdays, or for some reason need a "thrust." (I thought they were called "shout outs" but I guess I'm behind the times) It goes like this: he'll say, "Tina, your Mom wants you to know that she's thinking of you today while you start your new job. Congrats Tina! BAAAAAAAAMMMM! " Then he starts talking about the next person, always ending with another "BAAAAAAAAMMMMMM!" Now I am so out of it in the morning, and so amused by this whole thing that I end up participating, saying outloud to my radio, "Good for you Tina! BAAAAAAAM!!" It's so nonsensical! How did this get started? How can there be people in the area who wake up and think, "hey it's my husband's birthday! I have to call WHUR so that guy can yell BAAMMMMM to him!"