Levi Strauss CEO Michelle Gass was out for a run in San Francisco last March when she first heard the song “Levii’s Jeans” from Beyonce’s latest album, “Cowboy Carter.” “Literally, I got chills,” Gass recounted to CNBC, adding the name check represented a “once in a lifetime” marketing opportunity she couldn’t afford to squander. “She is one of the most celebrated and influential artists of our time … We asked the question, ‘Could there be something more?'” Six months later, Levi announced Beyonce would star in a new global marketing campaign. Then, a pattern that’s repeated itself since Levi invented blue jeans more than 150 years ago happened again: competitors raced to catch up.Gap and American Eagle launched their own star-studded campaigns the following summer in a bid to sell more jeans. Gap partnered with girl group Katseye in its viral made-for-TikTok “Milkshake” ad, while American Eagle chose actress Sydney Sweeney for its controversial “good jeans” campaign. Just before Thanksgiving, American Eagle launched another celebrity campaign with a different type of star: Martha Stewart. Some smaller brands that can’t pay for a name like Beyonce have gotten free marketing just from celebrities wearing their denim. In late August, Kylie Jenner posted a picture of herself in True Religion jeans, leading to a spike in sales, CEO Michael Buckley told CNBC. He called it the “ultimate compliment.” Industry wide, brands aired nearly 70% more denim TV spots this year compared to last, as the global jeans market swelled to $101 billion, up 28% since 2020, according to data from TV outcomes company EDO and market research company Euromonitor International. [embedded content][embedded content]Behind the big campaigns were hints about each retailer’s strategies and challenges. American Eagle is trying to win over more men. Levi’s wants to court more women. Gap is working to find relevance among a new generation of shoppers. But taken together, the marketing shows the lengths companies are going to dominate a growing denim category that is still up for grabs — even if Levi may have created it. In an economy where many shoppers are thinking twice before shelling out for a new pair of jeans, retailers are scrapping harder than ever to win every dollar they can. “There definitely is a denim war. There’s a war for people’s attention. There’s a war for people’s spend,” said Neil Saunders, retail analyst and GlobalData managing director. “Who has the most comfortable denim? Who has the softest feel? Who has the best cuts? What fits me well? There’s much more consideration in the customer buying process than for some other products, so it does make it much more of a battle between the retailers.” Why retailers are betting on denim nowLike all things in fashion, denim goes through cycles. It’s a stalwart garment in any closet, but sometimes it’s in fashion, and sometimes it’s not. The last time denim was this big was during the 2000s when brands like True Religion and Joe’s Jeans were a favorite among A-listers before athleisure became more popular and transformed casual dressing. “When we came out of Covid, I think to me this is really when it started, when we started to see consumers basically say, ‘Look, I want to feel like I am not sitting in my house anymore, I want to feel like I am getting dressed up to go out,'” said Janine Stichter, a retail analyst and managing director at financial services firm BTIG. “That kind of started to bring about the denim cycle that we’re in right now.” In past denim booms, certain cuts domi …