How to think like a radio guy, IV -- Ratings.

The spring Arbitrons are arriving right now. All over the country, station managers and program directors are watching their email inboxes, palms moist, brows tight. It's called The Book. You can read some stuff about Arbitron's ratings methodology here--sample listeners write their radio listening down in little diaries and send them back. What comes out every quarter is expressed in percentages of population--rating points--in all demographic groups; 18-24 men, 25-49 adults, and so forth. Advertising agency time buyers decide who gets what share of the money, using the numbers. For radio people, it's a profit or loss, job-no job situation.

To give you a feel for how radio people think about ratings, here's how one of the radio trade publications, AllAccess.com [warning--slow, cluttered site], headlined a couple of yesterday's fresh ratings results in their daily email:

"KIIS/KVVS Now No. 1"

[The L.A. station combination went from 4.6% (Winter 05) of the audience to 4.7% (Spring 05), beating KPWR, which dropped from 4.7% to 4.2%.]

"...KYXY Leaps from 3rd to 1st"

[San Diego: KYXY's Winter share was 4.5%. Spring: 4.8%. KOGO plummeted from 5.3% to 4.3%.]

These are not radical new radio stations bursting on the scene. These are not sudden "leaps." We're talking 1/10th to 1/2 of one percent leaps or dives here. Champagne corks are to be popped. What do you suppose the margin of error on these survey's is? I'm guessing plus-or-minus 3%, if I remember my Book-sweating days accurately. These are the ratings reports of top stations that have changed nothing major in years. Hello.
[For more on margin of error, look here.]