LOS ANGELES — Who was the least valuable player in last year’s Super Bowl? Viewers might say it was the tousle-haired young boy in the Nationwide Insurance spot, talking about all the cool things he missed because he was killed in a household accident.

Headline writers dubbed it the “Dead Kid” commercial. Social media buzzed with outrage. The company was forced to issue a statement explaining it didn’t mean to upset anyone. Nationwide’s chief marketing officer soon left his job.

Such are the risks of running a commercial in the biggest annual television event. But the advertisers who are paying close to $5 million per 30-second spot to be part of Super Bowl 50 on CBS this Sunday know that their high-profile role in the event means they are going to be judged as much as the players and coaches on the field.

“It’s absolutely nerve-racking,” said David Angelo, chairman of the Los Angeles ad agency David & Goliath, which produced a Kia Motors ad featuring Christopher Walken that will air Sunday. “You want to make sure you’re representing your client’s brand in the best way possible.”

The pressure has heightened because the Super Bowl is becoming a rare species in television: People watch it live instead of recording it for later or streaming it on a smartphone or other device.

When an average of 114 million viewers watched the New England Patriots’ heart-stopping victory over the Seattle Seahawks on NBC last year, it marked the sixth time in the past seven years that the Super Bowl has set a new record for the largest U.S. TV audience ever.

The game’s surging popularity has advertisers paying more each year to be a part of the surest bet to reach the most TV viewers in one shot.

Kantar Media reports Super Bowl ad spending has gone from $205 million in 2010 to $347 million in 2015 — a period where overall TV ad revenue growth has flattened out. The average cost of a 30-second Super Bowl commercial in that time has risen from $3.1 million to $4.4 million. Ad Age Datacenter projects spending on Super Bowl 50 will hit $377 million this year, with the average spot selling for $4.8 million.

At that price, advertisers need to deliver not just a commercial, but a piece of entertainment content that will compete for a place in the national pop culture conversation.

“When we’re working on a Super Bowl ad I tell our people to create something that will make you want to be able to stand in front of the TV set and tell everybody ‘shut up, my spot is on.’ It’s your time to shine,” Angelo said.

That need to stand out has also driven up the cost of making Super Bowl spots to $2 million and higher — a boon to Los Angeles-based post-production houses, producers, directors, animation companies and visual-effects shops used to enhance commercials.

This year’s batch includes a lineup of movie stars including Seth Rogen and Amy Schumer for Bud Light, Ryan Reynolds for Hyundai, Alec Baldwin for Amazon and rapper Drake in a T-Mobile commercial.

It wasn’t always this way. In the 1970s, networks that didn’t have the game could still earn massive ratings by airing first-time telecasts of theatrical movies such as “Gone With the Wind” and “The Godfather.” It was the era when ABC, CBS and NBC dominated, before the proliferation of cable, home video players and streaming services made almost every film readily available.

“The Super Bowl didn’t have much significance then,” said Joe Pytka, the Los Angeles-based director of dozens of Super Bowl ads. He recalls that the Academy Awards telecast was the most prestigious advertising platform until the early 1980s.

Many of the messages of the Super Bowl spots in those early years reflected the sober economic environment of the time and did not require spectacular creativity.