Viewers are used to seeing short ad spots on YouTube but rarely on TV, where 15, 30 and even 60-second formats are more popular with advertisers.
But now Fox Sports is offering brands six-second spots, saying that they could get more attention than longer commercials.
The network's President Eric Shanks told the New York Times this week: "When the six-second ads are placed in unique positions, it has the potential to gain even more attention than a traditional unit." The shorter ads are being sold as part of a package, and Times sources suggested the individual spots would cost as much as $200,000.
The new spots will run during the NFL's opening weekend, starting on September 10.
This comes in the face of millennials' short attention spans for advertising being only five or six seconds, according to a report by comScore.
"You're going to have to make your case literally in a matter of seconds and make sure you grab somebody's attention," comScore Chief Executive Gian Fulgoni told CNBC's "Squawk Alley" in July.
YouTube is also set to remove its 30-second non-skippable ad format from next year, because it wants to provide "a better ads experience for users online," according to a statement emailed to CNBC.
Although shorter TV ad spots have been available in other markets such as the U.K. for some time, they have been seen as poor value for money, according to Matthew Landeman, managing director of Carat U.K.
"In the U.K. technically we have been able to buy five-second TV spots for a long time, (but) very few advertisers choose to do so as they cost 35 percent of a 30-second (ad) and unless they are part of a series they can be hard to make work on the standard TV format," he told CNBC by email.
Landeman added that U.K. advertisers are keen on exploring TV innovations in relation to new technology for the length of an ad.
"Innovation in the U.K. is largely focused on how we use TV in new ways in relation to data, technology and across multiple platforms, genuinely leveraging the power of TV content along the way. While more flexibility in display formats would always be a good thing, it's not broadly the thing our clients are most hungry for," he said.
Fox Sports did not immediately respond to a request for comment when contacted by CNBC.