LOS ANGELES >> Advertisers who will be paying close to $5 million per 30-second spot to be part of Super Bowl 50 on CBS today know that their high-profile role 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 airs today. “You want to make sure you’re representing your client’s brand in the best way possible.”

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 seven years that the Super Bowl has set a record for size of the TV audience.

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 to $4.4 million from $3.1 million. Ad Age Datacenter projects spending on Super Bowl 50 will hit $377 million this year, at an average $4.8 million per spot.