• by Wayne Friedman , Staff Writer, May 14, 2007

U.S. viewers have given broadcast networks an offer they can't refuse this season: return low-rated shows to schedules, or start up new shows with the likelihood they will do even lower ratings.

No wonder Tony Soprano is not coming back -- business is tough all over.

As executives unleash new programming to advertisers in their upfront presentations this week, the probability is that many of this season's suffering rookie shows will continue. NBC will bring back "30 Rock," "Friday Night Lights" and "Scrubs." NBC will even stay the course for an 18th season of "Law & Order," which also dragged this season, forcing rumors that the longtime series is going to cable.

ABC will probably give another shot to "Knights of Prosperity," "Notes from the Underbelly," and maybe "What about Brian." Fox will give another try to the mostly 2-rated and below, "Til Death."

NBC, ABC and Fox will say during upfront presentations that these shows either have strong critical appeal, retain hard-to-get upper-income viewers, or have loyal young females as viewers.

Here's another reason -- one that they won't disclose: Networks have sunk lots of marketing dollars into these shows in an effort to build brand recognition, using anywhere from $4 million to $10 million worth of their respective promo time.

Increasingly, this becomes a game of diminishing returns -- higher costs at lower returns because of TV's continuing dirty little secret, broadcast erosion.

Depending on who you believe, broadcast ratings are down anywhere from 3% to 8% this season. At that rate, not only do individual program ratings drop -- but also the networks' marketing efforts become discounted by 3% to 8% as a consequence of using their own airtime.

Even Fox and its impossibly strong "American Idol" are finally feeling the pinch. "Idol" started up 5% in the key 18-49 viewers at the beginning of this year, and now, as it winds down for its sixth season this May, will probably dip in ratings for the first time in its history.

Years ago lower-rated shows were almost immediately jettisoned. The better plan now appears to be, stay the course and build on the few assets that you have. Of course, pessimists have another phrase for it: good money chasing bad.