• by Wayne Friedman , February 14, 2017

TV’s commercial ratings -- still the main currency that virtually all national advertisers use to buy national TV time -- was down by mid- to high- single-digit percentages for January.

Total national TV prime-time ratings among 18-49 viewers fell 5% to an average 26.05 million with total day 18-49 viewers sinking 9% to an average 15.5 million for Nielsen’s C3 metric -- average commercial ratings plus three days of time-shifted viewing.

Broadcast networks were flat in prime time and off 12% in total day data viewing among 18-49 viewers. Cable networks were down 7% in prime time and 7% in total day numbers.

For prime time, NBC was 7% higher to average 2.4 million 18-49 viewers, while CBS gained 6% to 2.3 million, ABC was up 10% to 1.5 million 18-49 viewers, and Fox sank 32% to 1.5 million. Fox had a difficult comparison to January 2016, when it ran highly rated series finales of “American Idol” and “X-Files.”

This ratings report, which came from MoffettNathanson Research, points to Nielsen’s integration of set-meter home data in December 2015 into Nielsen’s national sample -- its National Panel Expansion (NPX) -- as a main contributor for the decline, especially for cable networks.

“After a steadily improving trend through the fall, [prime time cable ratings] are now down to mid-to-high single digits. Last January we saw a sequential step up from December reflecting benefit of Nielsen’s NPX sample, followed by continued improvement through the winter.”

All major cable network groups lost ground among January prime-time C3 18-49 viewers -- 21st Century Fox; down 2%; Scripps Networks Interactive, 3%; Viacom, 4%; Time Warner, 4%; Discovery, 7%; A&E, 10%, NBCU, 10%; AMC Networks, 10%; and Disney, off 15%.