C3 ratings, the metric used for buying and selling TV advertising, fell 12% among 18 to 49 year olds in primetime in August, according to an analysis of Nielsen data by Michael Nathanson of MoffettNathanson Research.
In July, C3 ratings were down 13%.
Both broadcast networks and cable network showed 12% declines in the month in primetime. For total day, the broadcasters were down 13% and cable was down 16%, for an overall decline of 14%.
Among the broadcasters, Fox was the only gainer, up 2%. ABC was down 10%, CBS off 13% and NBC dropped 19%.
AMC was the only cable network group to improve in primetime, with a 3% gain. Other than Discovery, which was down 2%, the remaining cable network groups suffered double-digit decreases, with the biggest drop happening at WarnerMedia.
Among the top 25 rated cable networks in total day, only TLC and MTV showed increases. Kids’ networks were the biggest decliners with Cartoon, Adult Swim, Nickelodeon and Nick at Nite dropping the most.
Nathanson said pressure on the ratings was propelled by “massive drops” in People Using TV among younger viewers. PUT levels for people 18 to 24 fell 19% in August and PUT levels for 2 to 11 year olds was down 17%.
“Given the challenged ratings trends we have seen, we remain cautious on the TV advertising market’s ability to grow dollars by offsetting these declines with higher CPM inflation,” he said.
C3 ratings measure the average rating for the commercial time during programs. It includes live viewing, plus delayed viewing for three days.
Nathanson also took a look at the first week of NFL ratings.
Live plus same day viewership was flat at about with 16.25 million viewers, compared to 16.26 million a year ago. But he notes that a year ago, NFL ratings were reduced by the effects of Hurricane Irma, which cut viewing in markets including Houston.
CBS’s football coverage was up 28% from a year ago and Fox showed a 5% gain on Sunday. NBC’s Sunday Night Football was down 10% and Monday Night Football on ESPN dropped 7%.
“Given all the moving pieces behind the NFL’s first week data point, we would argue that it is too soon to draw any conclusions and wait for next week to see if this stability can continue,” Nathanson said.