AP Photo/Ric Feld,File
The episode started when Trump turned to Twitter on Tuesday to congratulate Fox News for "being number one in the inauguration ratings."
"They were many times higher than FAKE NEWS @CNN," he wrote.
CNN's public relations team responded to Trump's tweet, citing cumulative numbers from Nielsen
"According to Nielsen cumulative numbers, 34 million people watched CNN's inauguration day coverage on television. 34 million watched Fox News," the CNN communications account wrote in a tweet, which was shared thousands of times and became the basis for several news stories.
The next day, CNN host Chris Cuomo turned to Twitter to double down on the claim:
The cumulative number is technically correct. (CNN, however, did round it off. The precise numbers had Fox News with 34.4 million viewers and CNN with 34.2 million.) But it's a statistic rarely, if ever, used in the cable news industry, according to experts.
"It's a factual statistic, but I literally never used cumulative ratings once when I edited TVNewser," Brian Flood, a media reporter at TheWrap, told Business Insider in an email. "Not once."
Instead, it's most common for networks to provide ratings for a specific hour or program to boast about their audiences. That's the spot where Fox News handily outpaced CNN throughout Inauguration Day.
Take a look at some of the numbers from Nielsen:
12 p.m. to 12:30 p.m. (Oath of Office and Inaugural Address):
CNN: 3.375 million total viewers
Fox News: 11.768 million total viewers
11:00 a.m. to 1:00 p.m.
CNN: 3.047 million total viewers
Fox News: 10.483 million total viewers
1:00 p.m. to 5:00 p.m.
CNN: 2.326 million total viewers
Fox News: 7.901 million total viewers
Primetime (8 p.m. to 11 p.m.)
CNN: 4.528 million total viewers
Fox News: 6.958 million total viewers
Those numbers make it clear that Fox News easily outpaced CNN in inauguration ratings, almost tripling its numbers at some points in the day.
Before it engaged in a fight with Trump, CNN conceded that it came in second to Fox News in its own press release.
"CNN ranked a strong #2 in cable news during the Inauguration of President Donald Trump yesterday, January 20th," the press release said.
Erik Wemple, a media critic for the Washington Post, said he had "seen some of the silliness" over the ratings and noted that cable news networks often engage in "puerile spats" over such things. But he said that this time, CNN perhaps escalated it further than normal.
"When there's a fact-check of the president, it moves away from the realm of standard cable-news bickering," he told Business Insider in an email.
A CNN spokesperson declined to comment.
Fact: fox did not have bigger #InaugurationDay audience that CNN https://t.co/daJnWUN6G4
- Christopher C. Cuomo (@ChrisCuomo) January 26, 2017