The clock appears to be ticking on one of the most innovative developments in Super Bowl advertising in recent years: two-minute ads.

Advertisers like Fiat Chrysler Group and Samsung Electronics have flourished in recent Super Bowl outings by buying up a massive chunk of ad inventory to run cinematic commercials lasting 120 seconds in length. Given the recent cost of a 30-second Super Bowl ad berth, which stood at about $3.5 million in 2012, and soared to more than $5 million this year, the investment in such a format is substantial.

In Super Bowl LI, however, the two-minute behemoth may have transformed from a thriving species to one that has gone dormant. “I don’t believe there are any two-minute ads” currently on the roster, said Bruce Lefkowitz, executive vice president of ad sales for Fox Networks Group, in an interview. “It could just be that folks didn’t feel they needed that length for storytelling.”

Fox will air the game on Sunday, February 5. Advertisers slated to appear include Anheuser Busch InBev, Audi, Pepsi, Snickers and Procter & Gamble’s Febreze, Tide and Mr. Clean

Since 2011, when Chrysler took over an entire ad break in Fox’s broadcast of Super Bowl XLV so it could run a two-minute ad celebrating a rebirth of Detroit and the auto industry after a decimating recession, two-minute ads have become a Super Bowl staple. Fiat Chrysler Group made noticeable use of the tactic, running a memorable two-minute spot in 2012 in which Clint Eastwood told viewers it was “halftime in America.”

Samsung got in on the act in 2013, airing a two-minute long spot crammed with jokes from Seth Rogen, Paul Rudd, Bob Odenkirk and LeBron James. Not to be topped, Chrysler returned in 2014 with a two-minute vignette in 2014 featuring Bob Dylan telling those watching that “Detroit made cars, and cars made America.”

Asked whether any of its brands would appear during Super Bowl LI, Diane Morgan, a spokeswoman for Fiat Chrysler Group, said via email that “the company has no info to share at the present time.” During Super Bowl 50, Fiat Chrysler ran two 60-second ads – another signal the extra-long promotions have been falling out of favor. Samsung has not returned as a national sponsor of the game since its 2013 outing.

The use of longer ads peaked a few Super Bowls ago. According to Kantar Media, a tracker of ad spending, 40% of the ads in the 2014 broadcast of the Super Bowl lasted 60 seconds or more. Last year, that was true of just 26%.

Advertisers face a more challenging climate in the so-called “Big Game” than they have in years, thanks to an audience polarized by the most recent presidential election. In that sort of atmosphere, making the type of grand statements or dynamic efforts required to get people to stick around for two minutes may be futile. A two minute ad could cost around $20 million in this year’s broadcast. Who wants to blow that kind of money to alienate potential customers?

“The most famous recent two-minute ads were all deep commentary on America, Americans, and our way of life,” said Brian Sheehan, a Madison Avenue veteran who is a professor of advertising at Syracuse University’s S.I. Newhouse School of Public Communications. “In the current climate, I think it is very dangerous for any brand to make a deep comment on our society, or way of life, without being seen, or even implied, to be pro or anti-Trump. It says more about the sad state of our nation that it does about the state of Super Bowl advertising.”

One Super Bowl advertiser is testing the opposite tactic this year. Wonderful Company will air one 15-second ad each for its Wonderful Pistachios and Fiji Water at separate points in the game. That certainly could leave room in some ad breaks for an ad that lasts a minute and 45 seconds.

Fans of extended conversation can at least count on Ford Motor Co. The automaker will run a 90-second ad just before kickoff. The ad shouldn’t be counted as one of the true Super Bowl variety – the pre-kickoff spot costs significantly less than a commercial in-game – but few viewers will make that distinction.

During one of the few TV events in which consumers actually want to watch commercials, Ford executives think they can keep a fan’s attention, said Chantel Lenard, Ford’s director of U.S. marketing.  The 90-second ad “allows us to tell a bit of a longer story,” she said.  During the Super Bowl, “viewers want to listen and hear your message.”