Advertisers who've kicked the tires on Fox's six-second commercial executions are investing a good deal of money for just a few ticks of media exposure, but thus far the micro-spots appear to have had a disproportionate impact on audience engagement and recall.

T-Mobile, which last month used the six-second format to promote its hurricane relief efforts during Fox's coverage of the 2017 World Series, said results suggest that the short-form spots boosted viewer engagement metrics such as brand recall, likability and message recall.

Although there are other variables in the mix, T-Mobile's six-second spots during the World Series were twice as potent in recall and likability as the brand's standard ads in prime-time general entertainment programming, according to Ace Metrix data.

"It was hugely effective," says Nick Drake, T-Mobile executive VP of marketing and experience, who adds that the brand's overall mix of 30-, 15- and 6-second World Series spots resulted in the "most successful campaign we've run this year."

The fun-size T-Mobile spots aired in the double-box format during natural breaks in the action. For example, during the fifth inning of Game 5, as Dodgers pitching coach Rick Honeycutt paid a mound visit to try and soothe the nerves of struggling ace Clayton Kershaw, a magenta-tinged window appeared on the right side of the screen. Viewers were reminded that T-Mobile would donate $20,000 to Team Rubicon's hurricane relief efforts for every home run hit during the Dodgers-Astros series.

"As a call-to-action, the six-second spots were a great efficacy," Drake says. "They ran in game-play situations where the network could break in without intruding on the action, and so people really seemed to pay attention."

The company wound up donating nearly $2.6 million to the hurricane relief, roughly half of which owed to a viewer-tweet element promoted in World Series ads of various lengths.

Brands are now turning out to try the quick-play format in Fox's upcoming Thanksgiving Day NFL broadcast.

Duracell, which also ran six-second ads during the Series, and the personal finance company SoFi have snapped up some of the nine six-second opportunities Fox has set aside in its Thursday afternoon coverage of the Vikings-Lions game. According to Bruce Lefkowitz, executive VP of ad sales at Fox Networks Group, each six-tick spot is priced at the same rate commanded by a 15-second ad.

Also snapping up a single six-second sliver of airtime is Walt Disney Studios, which will air a mini trailer for "Star Wars: Episode VIII The Last Jedi."

"We're reducing one commercial pod in the game, and the goal is to have 54 seconds of interruption which will generate 135 seconds of revenue," Lefkowitz says, adding that Fox will present the Turkey Day spots in the same double-box format it used for T-Mobile's quickie World Series ads. "As always, we want to do everything we can to provide the best viewing environment for our fans and our advertisers."

Duracell was one of the first brands to give the six-second format a whirl, airing two of the micro-spots in Fox's Aug. 13 presentation of the "Teen Choice Awards." The battery brand's short-form ads in the World Series culminated with a brief salvo during the eighth inning of Game 7, as Astros catcher Brian McCann made his way to the batter's box to square up against Dodgers southpaw Alex Wood.

At the time Fox first announced its plan to introduce the six-second format to the "Teen Choice Awards," Duracell VP of Marketing Ramon Velutini said the company was looking forward to exploring their impact. "At Duracell, we are always looking at innovative ways to tell our story of trust, and drive value in our media investments," Velutini said. "We believe our 'power packed' six-second ads could play a bigger role in our creative asset mix in the near future."

For his part, T-Mobile's Drake says he envisions his brand looking to use the format as a means to experiment with a serialized narrative structure. "Live events lend themselves to that sort of sequential storytelling, so why not break out the creative over a period of time and tell a story over the course of the event?" he says.

While Fox does not disclose the average unit cost for its NFL broadcasts, the Tryptophan Day inventory comes at a premium. In 2015, the last time Fox aired the early Thanksgiving game (read: the afternoon broadcast that doesn't feature the Dallas Cowboys), the Eagles and Lions averaged 25.4 million viewers and a 12.3 household rating. Buyers estimate that the cost of a standard 30-second spot in Thursday's Vikings-Lions grudge match is around $900,000 a pop, which means the 6-second units priced out at around $450,000 a throw.

A Fox spokesman on Monday said "a few other brands" have signed on for the Thanksgiving Day quickies, and at least one of the short-form units is currently up for bid.

Also joining the six-second fray is Discover, although the financial services company is steering its short-form creative to Fox's college football coverage. Discover will unveil its first six-second spot during the Nov. 25 Ohio St.-Michigan showdown, running it twice, with plans to air the same unit twice in the Dec. 2 Big Ten Championship Game. Also set to air on Fox, the conference title tilt will feature Ohio State and the currently undefeated Wisconsin Badgers.

"The biggest thing we found with the six-second units that aired in the World Series was that when you have a combination of the right length and the right environs, you can really have a huge impact on how your message comes across," Lefkowitz says. "Given the lean-forward nature of live sports and the natural breaks that present themselves during baseball and football games, you clearly have an optimal environment—if you get the message right."