More than 111 million people are expected to watch the Super Bowl between the New York Giants and New England Patriots on Sunday—roughly a third of the U.S. population and the largest television audience in television history.
And virtually all of those viewers will be watching it live.
"Live sports is the most DVR-proof programming out there," Michael Learmonth, digital editor at Advertising Age, told Yahoo News, "which is why advertisers pay $100,000 a second to advertise there."
The cost of a 30-second spot during this year's Super Bowl was $3.5 million, up from an average of $3 million Fox charged during the 2011 broadcast. And NBC sold out its entire inventory of ad spots for Sunday's game before Thanksgiving.
One of the reasons the Super Bowl ads are so coveted is that they are guaranteed to be seen live by a massive viewing audience. Another reason: that the audience is just as likely to comment on them in real time, like the game itself.
For live television events—particularly sports—social media has become the ultimate second-screen for viewers.
"I was never big on DVR-ing sporting events because I'm tethered to the Web all day anyway," Jason McIntyre, founder of the sports, media and culture site TheBigLead.com, told Yahoo News. "And either by text or Twitter, there's no way to shield yourself from not knowing what happened."
The virtual water cooler of real-time viewing seems to be the main draw. Some 60 percent of viewers plan to use some sort of mobile device while they're watching the Super Bowl, according to a Harris Interactive study. According to an E-Trade survey, 31 percent plan to be on Facebook and another 6 percent on Twitter.
According to Twitter, the 2011 Super Bowl set a then-record for a sporting event of 4,064 tweets per second about the game. (Last month's playoff Tim Tebow-led playoff game between the Denver Broncos and Pittsburgh Steelers, with 9,400 tweets-per-second, shattered that mark.)
"You're sharing an experience," Brad Adgate, research director at New York-based Horizon Media, told Yahoo News. "Whether you're texting someone, or commenting on Facebook and Twitter during the game, you're engaging in co-viewership like you're talking to someone next to you."
At a media conference earlier this week, ESPN president John Skipper said the network's viewership is "99 percent live."
"Two weeks ago, my wife and I had plans during the NFC championship game, so I had to DVR it," Michael James, a sports fan from Amherst, Mass., recalled. "Later that night when I watched it I noticed I was really missing being able to pick up my iPhone and check my Twitter account. Definitely not as fun."
Watching live also deters "spoilers" from your Twitter stream.
"If you can't watch the game in real time—for instance, if you're tending to a 10-month old baby, and you've got to repeatedly pause the game—then you have to have your phone and computer in another room," McIntyre said. "This sounds like a silly statement, but if you're in the sports media business, it's true."
He added: "I'm a die-hard Jets fan, and there's no point in DVR-ing a game if you get dragged to an event at 2 p.m. on a Sunday. The best moments are up on YouTube within 10 minutes, and anything pivotal that happened in the first quarter has already been dissected many times over by the third quarter. It's sad, but from September to December, my social life on the weekends takes a massive hit."
Advertising and TV execs are hoping that this devotion spreads to to other genres and other nights of the week.
"I think what has a lot of network folks excited is the idea that people might watch '30 Rock' live because its more fun to watch when everyone else is," Learmonth said. "The water cooler happens in real time, not the next day."
The Super Bowl, though, is an anomaly, and the suits should be weary of drawing any big conclusions on viewing habits. "You really can't compare it to anything else," Adgate said. "It's unlike any other televised event."
During the Super Bowl, even the commercials are replayed. According to TiVo, which analyzes its second-by-second audience measurement data, the most replayed ad during last year's Super Bowl was a Snickers' "Logging" ad featuring Richard Lewis and Roseanne Barr.
But DVR data also underscores the importance of the "Did you see that?" live moment. According to TiVo, the most replayed part of the 2011 game happened on the field: Ben Roethlisberger's incomplete pass in the fourth quarter, cinching the Green Bay Packers victory.
And, eight years later, Janet Jackson's wardrobe malfunction during the Super Bowl halftime show is still the most-recorded moment in TiVo history.
Other popular Yahoo! News stories:
• Behind the scenes of the Puppy Bowl, Animal Planet's irresistible Super Bowl counterprogramming
• Wolf Blitzer talks to Yahoo News about the debates, the 'Magic Wall' and his rigorous exercise regime
• Ron Paul action figures! The best, worst and weirdest swag of the 2012 campaign