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 Fox Sports will run 6-second ads during the Cowboys-Broncos game. (Photo: Craig Barritt, Getty Images) 
 
 Viewers of Sunday’s Dallas Cowboys-Denver Broncos game will see what one Fox executive told USA TODAY will soon become commonplace in the network’s sports broadcasts: The six-second ad. 
 
 T-Mobile has developed multiple six-second spots that will bookend a more traditional 30-second ad from the mobile carrier. The ads -- which appear similar to online pre-roll ads -- will run during Fox’s America’s Game of the Week broadcast that will be seen by 81% of the country. 
 
 “I think this really shows that we are not married to a certain commercial length,” Bruce Lefkowitz, executive vice president of advertising sales for Fox Networks Group, said in a phone interview. “This is a new opportunity for advertisers, since it changes how ads can run in games. We are going to expand this to Major League Baseball broadcasts and every single NFL game starting next week.” 
 
 CLOSE Viewers of the Cowboys-Broncos game Sunday will see what one Fox executive told USA TODAY Sports will soon become commonplace in the network’s sports broadcasts: the six-second ad. 
 
 Earlier this year during a presentation to advertisers, Fox hinted that it was going to experiment with ad length during games. (There are already 15-second ads mixed with occasional 60-second ads during NFL broadcasts.) The six-second ads were tested during the Teen Choice Awards broadcast by Fox last month. 
 
 For T-Mobile, the experiment with six-second ads isn’t surprising. In recent years, the company has tried to position itself as the “Un-Carrier,” heavily embracing and experimenting with social media. CEO John Legere is particularly active on various platforms, including Twitter, where he has more than 4.5 million followers. 
 
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 "We know that short-form videos perform better in digital, and that consumer attention spans are increasingly shorter," Kari Marshall, VP of media at T-Mobile, said in a statement to USA TODAY. "So applying these insights to TV, and taking what we’ve seen with shorter ads to date, we’re very excited to partner with Fox to take it a step further." 
 
 T-Mobile is no stranger to the NFL. During last February's Super Bowl, it featured three minutes worth of ads that included celebrities such as Justin Bieber, Martha Stewart and Snoop Dogg. 
 
 Lefkowitz said the ability to grab viewers’ attention via the shorter spots, especially younger viewers, was “certainly” a consideration in the creation of the six-minute ad segments. 
 
 “We have done research on Millennials and how they interact to different types of messages,” Lefkowitz said. “You don’t always need 30 or 60 seconds to reinforce a brand’s message.” 
 
 The creation of the shorter ads also comes as the NFL attempts to recover from an 8% viewership decline last year. 
 
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 The NFL worked with its broadcast partners (Fox, CBS, NBC and ESPN) to cut down on commercial breaks -- although the breaks are slightly longer now -- among other changes to speed up the game. 
 
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 The pace of play did improve in Week 1 compared to the same time period last year. Only five of the 15 games in the opening weekend exceeded three hours, compared to 10 of 16 games last year. 
 
 PHOTOS: Best of NFL Week 2 ||||| Tom Brady of the New England Patriots celebrates after defeating the Atlanta Falcons during Super Bowl 51 in Houston last February. Credit: Kevin C. Cox/Getty Images 
 
 Visa has signed on to run six-second ads in Fox's National Football League game on Sunday and will use the shortened spot for its Hurricane Harvey relief efforts. 
 
 Visa will run one six-second spot right before kickoff and another during the game, according to Bruce Lefkowitz, exec VP-ad sales, Fox Networks Group. The host of Fox's pre-game show will intro the six-second spot before the game, while the other will run in a traditional pod within the game. 
 
 The short ad unit, first prominently championed by YouTube last year but adopted by others like Facebook in recent months, is part of Fox's strategy to figure out how to improve the TV viewing experience as it confronts competition from platforms with fewer or no commercials. 
 
 "As shorter-form ads have become more and more common in the digital ad space, consumers have become more accustomed to the format, and metrics show that they are more likely to retain the messages conveyed. It makes sense to take these learnings and apply them to the linear ad space as well," says Chris Curtin, chief brand and innovation officer, Visa, in an email. 
 
 "Good creative messaging should be able to be boiled down to simple takeaways for the consumer. So, building for short-form ad units has been a great exercise for our creative teams to ensure our messaging is laser-focused and crystal-clear," he adds. 
 
 Fox is charging similar rates for its six-second spots in NFL games as it does for 15-second ads. A 30-second ad in Fox's Sunday games goes for about $775,000 this season, according to ad buyers. 
 
 Fox plans on airing a limited number of six-second spots during NFL games this season, as well as in telecasts of Major League Baseball and college football and Major League Soccer on FS1. The company is close to signing deals with other marketers for six-second ads in NFL games through week eight, Lefkowitz says. 
 
 The network group began testing the format during its "Teen Choice Awards" in August. 
 
 In theory, most TV people agree that less commercial clutter is good for both consumers and advertisers. Fewer ads increase the chances that the spots will be remembered and decrease opportunities for viewers to change the channel. But there are plenty of questions surrounding the economics. In order to maintain ad revenue while decreasing ad loads, networks have to raise prices on the inventory. Marketers are far from convinced that they should pay more to be in a program with less commercial clutter. But Fox has been aggressive in moving quickly with adopting the format to prove its value. 
 
 In the spot that will air on Sunday, Visa is asking viewers to join in Harvey relief efforts, for which the company has committed $1 million. 
 
 "We collectively decided that it didn't feel right to launch an ad on behalf of our brand in the context of what is occurring in the Gulf states," Curtin says. ||||| Captains of the San Francisco 49ers and the Dallas Cowboys stand at midfield for the coin flip prior to a game in Santa Clara, California, on Oct. 2, 2016 
 
 TV networks are giving away more commercial time this NFL season than a year ago to make up for one of the worst ratings declines in a decade, a rare sign of weakness for the biggest draw on television. 
 
 In September, as the presidential election diverted viewers to cable news outlets, viewership of the NFL’s prime-time games dropped 14 percent from a year earlier among the coveted 18-to-49-year-old demographic, according to a Bloomberg Intelligence analysis of Nielsen data. Ratings for CBS’s Thursday night games fell 15 percent, NBC’s Sunday night games slid 12 percent and ESPN’s “Monday Night Football” plunged 16 percent. 
 
 When TV networks sell commercials, they guarantee advertisers a certain number of viewers. If they don’t fulfill their promises, they must offer free commercial time elsewhere to make up for it, potentially missing out on revenue from selling those ad spots instead. 
 
 So far this NFL season, TV networks have missed their estimates by about 20 percent, requiring them to offer advertisers what the industry calls “make-goods,” according to one ad buyer who asked not to be identified discussing private information. 
 
 A larger-than-expected number of make-goods so far is stoking concern that the NFL may be in trouble. Last year, one buyer purchased 100 NFL ad spots and got six free commercials to make up for ratings that fell short of estimates. This year, that same buyer acquired 100 ad units and expects to get about 10 make-goods. 
 
 The decline in NFL viewership raises new questions about the invincibility of live sports at a time of great anxiety for the media industry, marked by a loss of subscribers to conventional cable and satellite services, falling broadcast-TV ratings and fierce competition from digital outlets. And National Football League games aren’t alone. The Olympics on NBC and the U.S. Open tennis tournament on ESPN also drew fewer viewers than previous years. 
 
 Representatives from Comcast Corp.’s NBC, CBS Corp., Twenty-First Century Fox Inc., and Walt Disney Co.’s ESPN declined to comment on the ratings decline and offering make-goods. 
 
 Media companies have spent $57 billion for the rights to air the NFL into the next decade because those games have historically drawn massive live audiences, so advertisers are willing to pay top dollar to broadcast their marketing messages during commercial breaks. 
 
 The price of a 30-second TV spot on NBC’s “Sunday Night Football” costs about $674,000 on average, making it the most expensive commercial time on television, according to Ad Age. CBS’s “Thursday Night Football” is the second-most expensive, fetching an average $523,000 for 30 seconds. 
 
 To be sure, the NFL is just a quarter of the way into its season. And professional football is still the most-watched programming on TV. The networks point out that they offer make-goods every year, and can do so without hurting their revenue. That’s because NFL ad rates are so high, and there are so many games, that inventory rarely sells out, leaving a cushion of unsold commercial time to make it up to advertisers, one ad buyer said. 
 
 Network Deal Value Per Year Term Program ESPN $15.2B $1.9B 2014-21 Monday Night Football CBS $9.6B $1.09B 2014-22 AFC package FOX $9.7B $1.08B 2014-22 NFC package NBC $8.6B $0.96B 2014-22 Sunday Night Football DirecTV $12B $1.5B 2015-22 NFL Sunday Ticket Verizon $1.0B $0.25B 2014-17 Streaming CBS, NBC $0.45B $0.225B 2016-17 Thursday Night Football Twitter $0.01B $10M 2016 10 games Total $55.6B $7.0B 
 
 There could also be a silver lining for the networks: The weak NFL ratings could inflate ad prices across the rest of the marketplace. When TV networks give away commercial time to advertisers, they could then reduce the supply of ads during other programming, making prices across the board go up. 
 
 Yet if the ratings slide continues through the season, TV networks could be forced to charge less for NFL ad rates next year -- and beyond. ESPN’s contract with the NFL runs through 2021, while CBS, Fox and NBC have accords with the league through 2022. CBS and NBC also have a deal to split the broadcast rights for Thursday Night Football, which expires in 2017. 
 
 Reason for Decline 
 
 No one can point to a single reason why ratings for prime-time NFL games have fallen this season. TV networks blame weak match-ups, non-competitive games, the rise of online streaming and the presidential election. 
 
 Whatever the reason, not all live football games are feeling the same effects. Through five weeks, Disney’s ABC Saturday night college football games are averaging 6.1 million viewers a game, 28 percent better than the next-best window on any other network and up 3 percent from the first five Saturday night broadcasts last season. One the whole, ratings for ESPN’s college football games are flat. 
 
 But college football hasn’t had to compete with Donald Trump and Hillary Clinton, at least not head to head. ESPN’s Sept. 26 “Monday Night Football” game between the New Orleans Saints and Atlanta Falcons aired at the same time as the first presidential debate, an event that drew a record-breaking 84 million viewers. By contrast, the Saints-Falcons match-up garnered the lowest viewership for Monday Night Football in at least 25 years, with about 8 million viewers. This Sunday, NBC’s “Sunday Night Football” featuring the New York Giants and Green Bay Packers comes up against the second presidential debate, and many are expecting weak ratings. 
 
 Some advertisers and marketers say there may be too many football games being broadcast in too many places, diluting the overall audience. The NFL, for example, expanded Thursday Night Football broadcasts from eight to 10 games this year. Twitter’s live stream to more than 2 million viewers may have eaten into ratings for “Thursday Night Football” on CBS, according to Bloomberg Intelligence. 
 
 It’s still early in the NFL season, and viewership could pick up when match-ups improve and the election is over. 
 
 “The numbers are going to come back and we’ll see an uptick as we go forward this season,” said Andy Donchin, chief domestic investment officer at ad-buyer Amplify US. “The NFL is too popular.” 
 
 — With assistance by Eben Novy-Williams
– Having already killed everything from golf to Applebee's, it looks like millennials have their sights set on the 30-second ad spot. AdvertisingAge reports Visa ran two six-second ads during an NFL game on Fox last Sunday. And T-Mobile will follow suit during this Sunday's Dallas Cowboys game on Fox, according to USA Today. The six-second spots, which Fox first experimented with during the Teen Choice Awards last month, "appear similar to online pre-roll ads." And one Fox executive says they're about to be commonplace on the network: "This is a new opportunity for advertisers, since it changes how ads can run in games. We are going to expand this to Major League Baseball broadcasts and every single NFL game starting next week." Six-second ads were first pushed by YouTube before being adopted elsewhere on the web. A Visa executive says research has shown viewers remember the messaging better in short bursts, and that Fox executive says the six-second ads could appeal to millennials and their shorter attention spans. "We know that short-form videos perform better in digital and that consumer attention spans are increasingly shorter," a T-Mobile executive adds. Thanks to cord-cutters and DVR's ability to fast-forward through commercials, Fox had little choice but to try something new, Fortune reports. Fox has said it may insert the six-second ads into down moments of the games themselves, which could make them both harder to skip and allow the actual commercial breaks to be shorter—a bonus for viewers.