[NEW YORK] A record 84 million people tuned in to US television networks on Monday night for the first presidential debate between Hillary Clinton and Donald Trump, a huge audience rarely seen on TV in the age of digital streaming and social media.
The estimated ratings figure from Nielsen included people watching the raucous face-off across 13 US cable and broadcast networks and public television station PBS.
The audience beat the 80.6 million record set by the Jimmy Carter-Ronald Reagan TV presidential debate in 1980 but fell short of the 100 million viewers some analysts had predicted for the event.
The TV figures did not include millions of people who watched the encounter online through Twitter, Facebook and other social media, including in large groups in bars and restaurants.
The National Football League's annual Super Bowl attracts more than 100 million viewers, making it the biggest US TV event.
Monday's debate was the first of three scheduled between Democrat Clinton and Republican Trump before the Nov 8 election. The other two are set for Oct 9 and 19.
Fox News Channel grabbed the biggest cable audience with an average 11.4 million viewers, early Nielsen data showed.
NBC, whose Nightly News anchor Lester Holt moderated the contentious exchanges about race, the economy and national security, was first overall with an estimated audience of 18.2 million.
TV networks had promoted the debates for days beforehand and reported strong demand compared with four years ago for commercial time during pre- and post-debate programming. Ad rates were far higher than for typical news programming.
CNN charged more than US$55,000 for 30-second ad spots as part of packages ranging from US$800,000 to US$1 million that included future debates and election night, according to a person with knowledge of the matter.
CBS charged between US$200,000 to US$225,000, according to another source.
Both CNN and CBS have limited availability left for the next debate on Oct 9, the sources said. "Clearly the debate did really well last night," said Michael Law, managing director of video investments at Dentsu Aegis Network.
Mr Law said he did not expect ad rates for the next debate would rise significantly based on Monday night's audience. The Oct 9 face-off airs against an NFL matchup of two popular teams - the Green Bay Packers and New York Giants.
"The NFL will likely do well on that night, but will probably see some fall-off during the 90 minutes of debate," Mr Law said.