Diet Coke’s comeback—how social media and new ad spending are reigniting the brand

Reports of Diet Coke’s death may have been greatly exaggerated. Despite consumer uncertainty over the sweetener aspartame, competition from Coke’s insurgent Zero Sugar sibling and a reputation that it had become a drink for baby boomers, Diet Coke is fizzing back to life behind an unexpected role as a social media accessory for Gen Z influencers. Its growing profile has captured the attention of Teen Vogue and Cosmopolitan, the latter calling Diet Coke “the trendiest drink of 2025.” See all of Ad Age’s 2025 Agency A-List winners here The brand’s newfound relevance began in 2023 when online fans started talking about Diet Coke as though it were a perishable food—speaking admiringly of “marinating” their Diet Coke in the refrigerator for days to accentuate the “crispy” feel of its carbonation. Fans online also debate the merits of Diet Coke from a can or bottle, discuss serving etiquette and rank the restaurants where Diet Coke can be purchased. The brand was also the featured base in a viral “dirty soda” social post from singer Dua Lipa, who mixed pickle juice and jalapenos with her Diet Coke on ice. @linds_wing @McDonald’s #dietcoke #crispydietcoke #mcdonaldsdietcoke ♬ original sound - LINDSEY WING Coca-Cola moved to cash in on these trending moments. A campaign called “Love Language” debuted in the second half of last year and romanced the taste of Diet Coke using the words online fans used to describe it, and the attention helped to get sales going again. Now, the brand is updating its “Diet Coke break” concept in a series of new ads called “Know the Signs.” This, too, has a connection to social activity through the popular #DietCokeBreak hashtag. “There’s a renaissance of interest from consumer, from the young consumer. We see it on social,” Sue Lynne Cha, VP of marketing for Coca-Cola trademark, said in an interview. “We want to make sure that we’re supporting this brand with advertising that celebrates the amazing taste that consumer loves, and celebrates the power and the positivity that it can bring in people’s lives.” Back in the 1990s, the “Diet Coke break” was relayed in famous TV ads showing office workers gathering at the windows to ogle construction workers having a Diet Coke on their break. Today, work is a solitary and hectic pursuit—taking place in homes or offices where people eat at their desks, rush out mistake-filled emails and don’t have the time to fix their hair. That’s where “Know the Signs” is set. “We are really reflecting on today’s culture, today’s workplace—it’s always on,” Cha said. “You’ve got to be productive at all times. And we know from Diet Coke lovers that when you have a Diet Coke break, it really makes a massive difference in your day. It’s that small thing that really keeps you going.” Three ads, each narrated by actress and comedian Kristen Wiig and directed by Fiona McGee, tell stories of small workplace challenges and the reward of taking a break. Each ad includes the phrases “make time for you time,” and “this is my taste.” The ads were created by WPP Open X, led by Ogilvy, and supported by Hogarth and GroupM in collaboration with Arts&Sciences, Human, Method and UTA Marketing. The ads, in 30- and 15-second cuts, will air on linear television, owned social channels and out-of-home. They are part of what will be an increase in Diet Coke marketing spend vs. last year, although Cha didn’t specify figures or the magnitude of the change. Recent news: Coca-Cola Co. reviews US media account Diet Coke’s U.S. measured media spending is up dramatically in recent years, per Media Radar, which showed support at $2 million in 2022, $16 million in 2023 and $18 million last year. “Since we started the ‘Love Language’ campaign, we’ve seen a really strong turnaround on the brand,” Cha said. Diet Coke volume was down by 2.7% through the first half of 2024 but improved to a 1.5% decline by the third quarter and finished the year down 0.1%, according to Beverage Digest. Coca-Cola CEO James Quincey marveled that “even Diet Coke grew” when reviewing its carbonated drinks portfolio in North America during the company’s third-quarter earnings call. Trademark Coca-Cola products, or all those that include the Coca-Cola name, grew North America case volume by 1% in 2024 vs. 2023, the company stated in its annual report. Diet Coke last gained volume in 2020, Beverage Digest figures show. Its share of the U.S. carbonated soft drink market dipped from 6.7% in 2019 to 6.2% in 2023 to 6.1% in 2024. Distinct tastes and audiences Diet Coke for several years had been behind other brands in terms of advertising support from Coca-Cola, Cha said, notably the fast-growing Coca-Cola Zero Sugar, which is quickly gaining on Diet Coke in market share (Diet Coke is the fifth-largest carbonated soft drink brand in the U.S.; Coca Cola Zero Sugar is No. 7, according to Beverage Digest). “We had a very strong focus on other portions of our portfolio, which were right for the time,” Cha said. “Now, we’re tapping into what made Diet Coke strong historically while bringing some newness and youthfulness to the campaign.” Cha said Diet Coke and Coca-Cola Zero Sugar have distinct tastes and distinct audiences. “We realize there is room for both,” she said. The “Love Language” ads focused on what makes Diet Coke’s taste experience unique—“Fizz and flavor,” an “electric crackle of carbonation” and a “crispy” sensation. The ads appeared to acknowledge social posts from influencer Kristen Hollingshaus, who popularized the “marinated” Diet Coke. @hauskris IT’S SO IMPORTANT TO MARINATE YOUR DIET COKES ‼️ #dietcokebreak #dietcoke #crispydietcoke #dietcokeaddict #dietcokebreaks #truelemonpartner #dietcokegirl #asmr #vlog ♬ original sound - hauskris Diet Coke’s tribe of fans includes polarizing figures such as Elon Musk and President Donald Trump, and some of its challenges remain, notably debate over aspartame, which is approved for use in the U.S. but has been shown in some studies to be a possible carcinogen. A bill now in Oklahoma’s state legislature would ban aspartame among a long list of synthetic food additives. Other diet drinks, such as Coca-Cola Zero Sugar and Sprite Zero Sugar, also include aspartame as a sweetener. See all of Ad Age’s 2025 Agency A-List winners here

Diet Coke’s comeback—how social media and new ad spending are reigniting the brand

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