NEW YORK — You don’t have to be a football player to be a part of the action on Super Bowl Sunday.

Coca-Cola is asking people to vote for an online match between three groups competing in a desert for a Coke on Game Day. Pepsi and Toyota are using viewers’ photos in their ads. Audi let people choose the end of its Super Bowl ad, while Lincoln based its spot on more 6,000 tweets from fans about their road trips.

“We drove passed an alpaca farm, a few of them were meandering on the highway and my sister screamed, “It’s the Alpacalypse!”),” reads one tweet in Lincoln’s Super Bowl ad that features rapper Joseph “Rev Run” Simmons and Wil Wheaton, who acted in the iconic science-fiction series “Star Trek: The Next Generation.”

Advertisers have found new ways to get viewers into the game online. And they’re going well beyond encouraging fans to tweet or “like” their ads on websites like Twitter Facebook.

They’re trying to get the most of their Super Bowl ads, which cost nearly $4 million a pop. Companies that advertise during the Super Bowl get a 20 percent increase in Web traffic on the day of the game, according to the analytics arm of software maker Adobe. They also have a higher online audience than average in the week after.

“We’re seeing better and more unique ways of getting people involved,” said Robert Kolt, an advertising instructor at Michigan State University. “You want people to be engaged.”

PepsiCo, which is sponsoring the Super Bowl halftime show, said its goal was to create buzz online with a monthlong campaign that went well beyond a voiceover saying “brought to you by Pepsi.” T

For about two weeks, Pepsi asked fans online and via a digital billboard in New York’s Times Square to submit their pictures for a chance to appear in a 30-second “intro” spot to air right before the halftime show.

The company said the effort was more popular than it expected: Pepsi expected to get 2,000 photos, but got 100,000 instead. About 1,000 photos were chosen to be a part of the intro, one in each frame of the spot, 15 frames a second, stitched together in “flipbook” style video that appears to show one person jumping to the tune of Beyonce’s “Countdown” song.

“We don’t just want (viewers) on pepsi.com, we want them telling their friends ‘I just did something with Pepsi,” said Angelique Krembs, vice president of trademark Pepsi marketing. “You want the friend to tell the friend about Pepsi. You don’t want Pepsi to always be the one talking about Pepsi.”

Coca-Cola created an online campaign that pits three groups — a troupe of showgirls, biker style badlanders and cowboys — against each other in a race through a desert for a Coca-Cola.

Starting Jan. 23 and continuing until the end of the Super Bowl, viewers can vote online for their favorite group. The group with the most votes will be revealed in an ad after the Super Bowl ends. And the first 50,000 voters will get a free Coke if they register for Coke’s loyalty program.

The campaign is more interactive than Coca-Cola’s online effort last year, which featured a real-time animation of Polar Bears reacting to what was happening during the Super Bowl.

“Last year’s effort was much more passive. It was you watching bears watching the game,” said Pio Schunker, senior vice president of integrated marketing. “This year we thought, ‘Can we up ante on the fun factor by handing the reins over to consumers?”’

Audi let viewers choose one of three possible endings for its Game Day spot by voting online on Jan. 25 for 24 hours.

The ad shows a boy who gets enough confidence from driving his father’s Audi to the prom to kiss his dream girl, even though he is then decked by her boyfriend. Audi allowed people to vote for one of three potential endings for the ad.

In one possible ending, the boy drives home alone in triumphant. Another ending shows him palling around with friends. The third shows the boy going home and finding a prom picture of his parents in which his dad has a similar black eye.

The first ending, called “Worth it,” won.

Audi, which declined to say how many people voted, said “Worth It,” was by far the most popular, getting more than half of the total views and the most “thumbs up” out of all three versions

“This year, Audi wanted to elevate fan interaction by allowing them to take part in the creative process and have a voice in how our spot should end,” said Loren Angelo, Audi’s general manager of brand marketing. “

The strategy seems to be working. On YouTube, the Audi ad is the third-most viewed Super Bowl ad so far, with 2.5 million views, behind a Toyota ad staring Kaley Cuoco of CBS’ “The Big Bang Theory” and a teaser for Mercedes-Benz featuring supermodel Kate Upton, according to YouTube.com