BOSTON: An ad created for Hershey's, the confectionery giant, engaged viewers more than any other aired during the Summer Olympics, according to a study which tracked people's facial expressions as they watched them.

Emotion measurement firm Realeyes worked with Lucid, an audience research platform, to monitor the emotional responses of 4,500 viewers via webcams.

Some 49 key facial points were analysed as the study participants watched 66 ads from Olympic and Team USA sponsors and ambush marketers.

Based on the results, Hershey's "Hello From Home" ad received a score of 92.5% for engagement, in terms of how successfully it grabbed viewers' attention, kept it and whether it left a lasting impression.

The ad featured US gymnast Simone Biles, who went on to win five medals at the games, and its light-hearted theme proved to be a hit with those who watched it.

"Hershey's winning effort appeals because it doesn't hit you over the head with the blood, sweat and tears narrative normally seen for these types of events," said Mihkel Jäätma, CEO of Realeyes.

"The relatively light-hearted approach proved especially appealing to women, scoring a near perfect 10 for them compared to 'just' 8 for men," he added.

Joint second place, with a score of 90% each, went to the "Hopeful #LikeYou" ad from TD Ameritrade, the online broker, and Panasonic's "Neymar's Challenge - Vol. 2 Blind Soccer".

The Panasonic ad was also the most emotionally engaging for younger viewers aged under 29, while TD Ameritrade, Team USA sponsor, was the only brand to make both the top 10 and the bottom 10 (58th place).

Although these top three Olympics ads all scored in the top 10% ever measured by Realeyes, the company still found that Olympics ads overall scored less well than Super Bowl ads.

"Although the Olympics is one of the biggest events for brand advertising, from an ad perspective the Super Bowl has evolved from just a sporting event to mainstream entertainment," Jäätma explained.

"Consequently, Super Bowl ads now have very little reference, if any, to the actual sport, whereas Olympic ads have to remain strictly 'on message' which perhaps limits their creative breadth."

Data sourced from Realeyes; additional content by Warc staff