Seeking to consolidate its appeal among existing fans and reinforce TV viewing habits, Major League Soccer has adopted a new stance for its 2016 promotional campaign.

"Stand as one" is the tagline, replacing last year's "Unstoppable" in creative ranging from commercials to digital banners, social skins, player-promo vignettes and other assets.

An anthem spot from The Brooklyn Brothers heralds the season's March 6 kickoff and touts Sunday telecasts on ESPN, FS1 and Unimás. The ad mixes high-octane game footage with shots of fans jumping to their feet and rocking the stands. "Sundays, we stand out," the voiceover says. "We stand all 90 minutes. Sundays, we stand and shout. Sundays, we stand with game changers, with the future. Sundays, we stand in awe. Sundays, we stand as one."

Despite losing $100 million annually by some accounts, MLS has made important strides. Last year, the league saw average game attendance rise almost 13 percent and enjoyed double-digit TV ratings gains, strengthening its pitch to potential advertisers. Its "Unstoppable" campaign helped drive that success, as did lingering World Cup buzz and the arrival of new teams including New York City FC.

For 2016, however, MLS' marketing strategy has evolved as it seeks to consolidate gains and sustain momentum.

"For the upcoming season, we wanted to pivot to a unifier that was rooted in engagement and advocacy, not just a motivating statement," Vincent Giamartino, group account director at The Brooklyn Brothers, told Adweek.

As part of the brand platform shift from declaration to participation, "we had to provide fans and clubs with more tools that they could rally around, specifically in the digital space," said Giamartino. "That's the native environment for the vast majority of MLS fans," which number about 20 million to 25 million, according to league estimates, with most of those in the multicultural millennial demographic.

Items include customizable wallpapers representing the league's 20 teams and its various stars—"I stand with NYC FC," for example—driving excitement at the local level for clubs and fans.

MLS also will up its mobile game, said CMO Howard Handler. Overall, 65 percent of MLS' paid media impressions in 2015 were on mobile platforms. For the new season, Handler plans to "maximize our coverage on mobile through social media, mobile banners and app integrations. We will work with key partners to identify more opportunities to create custom user experiences that are optimized for mobile."

To drive deeper engagement on second screens around key events like the MLS All-Star Game and playoffs, initiatives will include running real-time Twitter ads, full-screen takeovers and mobile countdown clocks.

"The use of 'Stand' as an anchor to frame our communications is really important," said Handler, because MLS is pitching fans on a lifestyle and culture as much as a sports experience. "We aren't just selling what happens on the field. The stadium energy and supporter culture is key to what makes us unique."

Michael Colangelo, assistant director of the USC Sports Business Institute, applauded the focus on "being part of the soccer community. It shows the league can reach and interact with the U.S. soccer community in multiple ways."

Robert Passikoff, president of the Brand Keys consultancy, believes the campaign does a good job "reinforcing values of people who are already fans" but questioned its ability to broaden MLS' appeal.

"There's something like 80 million soccer fans in North America, and about 20 [million] to 25 million of those are MLS fans," said Giamartino. "The priority was to move existing fans up the ladder, versus bringing new fans in."