Sweeps periods aren’t what they used to be, back in the old days when networks loaded up May with big miniseries, and stations resorted to the trashiest of come-ons seeking to entice viewers to watch.

Still, the remnants of the system haven’t been eradicated entirely, as demonstrated by the sleazy-as-dad-used-to-make-’em radio promo KCBS in Los Angeles ran on Tuesday, promoting its 11 o’clock news.

After plugging its high-rated Tuesday primetime lineup, the station mentioned an unidentified “epidemic” that is afflicting newborns. “How to avoid the new epidemic impacting babies!” the announcer droned, offering no clue as to what that might be.

In demographic terms, it’s hard to think of a more cynical tease to attract viewers. After all, who do local TV stations desperately want to reach to boost their ad rates? Younger women. And who’s most likely to have a baby in the home? Ding!

Of course, if the threat was really serious, you would sort of hope they wouldn’t force you to wait until 11 p.m. to find out, especially since the promo aired on a newsradio station (KNX-AM 1070) that, like KCBS, is owned by CBS Corp. If it’s an epidemic, shouldn’t you warn parents now, and fill in the details later?

So what was it? Flat-Head Syndrome, a non-fatal, treatable condition that has “skyrocketed” in the last two decades, the reporter said, without providing any information regarding precisely how prevalent it is.

Moreover, KCBS considered the story so important it didn’t show up until halfway through the newscast, after coverage of an hours-old high-speed chase (in L.A., we use those to rock us to sleep), a YouTube crash, a lawsuit related to Michael Jackson’s death, and a custody battle over a five year old, among others. Anchors Paul Magers and Pat Harvey only compounded the insult with empty crosstalk about how much they learned from the piece — before moving on to the important stuff, weather and sports.

Admittedly, KCBS isn’t the only station engaging in these sorts of lame teases (far from it), but it’s a good demonstration of the absurd depths to which local broadcasters still plunge in their desperation to lure in viewers — relying on pitches not much better than “An asteroid might hit the Earth … um, you know, eventually.”

Inasmuch as I suspected the epidemic was something less than that, I only tuned in out of curiosity to see just how misleading the promo was.

As for viewers who were actually drawn in by it, an old adage comes to mind — the one that begins, “Fool me once, shame on you….”