NIKE'S 'UNLIMITED' SERIES ABOUT EVERYDAY ATHLETES WAS THE MOST REMEMBERED OLYMPIC AD

To determine the most effective TV spots of the Olympics, Google tracked the top 12 brands with ads that aired during NBC's broadcasts by length and frequency, including Coca-Cola, Nike and BMW.

Collectively, the ads generated 3.5 billion impressions. The company's data includes online surveys as well as traffic stats about Google searches.

Per Google's findings, 34.4 percent of consumers remembered seeing Nike's "Unlimited" campaign, which champions the stories of everyday athletes like Chris Mosier, Sister Madonna Buder and Kyle Maynard—the first quadruple amputee to climb Mount Kilimanjaro.

Almost 33 percent of consumers remembered Coca-Cola's "That's Gold" ad, and 21.3 percent of people recalled a McDonald's ad.

Procter & Gamble's "Small Can Be Powerful" spot for Tide featuring American gymnast Simone Biles also performed well—roughly 22 percent of people remembered seeing the ad, and it had a 50 percent product-recall rate. After seeing the ad, 28 percent of consumers said that they were more likely to look for more information on the product or even buy it. Another 25 percent of respondents said that they felt "more positive" about Tide after seeing the ad.

To determine which brands viewers searched for the most, Google crunched a brand's share of searches by its share of impressions to create a stat called response index. BMW'sOlympic version of "Defy Gravity" had a score of 3.2, making it the most-searched brand. Coke and McDonald's were also highly searched brands, with scores of 2.0 and 1.6, respectively.

Google also dug into the differences between Olympic sponsors and non-sponsors. For official sponsors, purchase intent increased 25 percentage points between someone who saw an ad and those who did not. And for non-official sponsors, purchase intent between a control and exposed group jumped 32 percentage points.

For both official and non-official sponsors, Olympic ads heavily boosted sentiment for the brand. When asked, "Did the ad change how you feel about the brand," non-sponsors saw a jump of 27 percentage points for consumers who saw their ad. Ads for official sponsors, meanwhile, increased positive sentiment by 24 percentage points.

As more of Google's searches move to mobile, smartphone-generated queries particularly spiked during this year's games. Eighty-three percent of Google searches about Olympics ads came from smartphones, with another 10 percent coming from tablets and desktops making up the remaining 7 percent.