Dhar Mann, the creator of a YouTube channel with more than 25 million followers, first heard about the Cannes Lions advertising festival last year from a couple of friends.

“It was incredible — the amount of brands they met, the amount of opportunities that they walked out getting,” Mr. Mann, 41, said. So this year, he and his wife and the chief executive of his 200-person company, Dhar Mann Studios, flew themselves to the south of France for dozens of meetings with marketers and agencies.

The goal, he said, was to land long-term sponsorship deals for his YouTube channel. Marketers, he said, were keen to take the meetings and learn about his videos.

Mr. Mann’s company has primarily made money through ads on YouTube, he said, but wants to expand revenue, particularly as marketers grow increasingly interested in working with creators to reach consumers.

“Folks are realizing that creators have something special with their audience that paid media can’t get you,” Mr. Mann said.

Creator marketing — the business in which brands pay popular social media personalities to promote their wares — has long been a fixture on Instagram, YouTube and TikTok. But social media stars are playing a bigger role in the ad industry than ever, in an era when shows like “Saturday Night Live” are drafting talent from TikTok and television ratings continue to erode.

The energy was on display this week at Cannes Lions, a major event for the media and tech industry, as social media stars from Amelia Dimoldenberg to Jake Shane made appearances, ad holding companies hailed their creator agency purchases and Forbes unveiled its newest “Top Creators List” at a party where more than a few attendees appeared to be trailed by their own photographers. TikTok flew in creators like the Nigerian chef @chefabbys for panels and meetings, including face time with the company’s chief executive, Shou Chew.

”Influencers are everything,” said Craig Brommers, the chief marketing officer of American Eagle Outfitters. “I don’t care if you’re a bank, health care, anything — everyone is working with influencers.”

While plenty of companies, especially in beauty and fashion, have tapped influencers for a decade now, the scale is new. Unilever, one of the world’s biggest advertisers and the owner of brands like Dove and Hellmann’s, made waves earlier this year when its chief executive said that half its marketing spending would become “social-first” and that the company would work with 20 times as many creators as it had in the past.

“It’s a significant part of the marketing transformation we’re driving, which is moving from the old ‘one to many’ communication model — which is one message broadcast to many people — to what we call ‘many to many,’” Esi Eggleston Bracey, Unilever’s chief marketing officer, said in an interview this week.

Major ad holding companies have also gotten in on the action, suggesting that the Don Drapers of the world need the Alix Earles. Publicis recently announced the acquisition of the creator agency Captiv8 after buying another agency, Influential, last year. WPP has bought Obviously, the Goat Agency and Village Marketing — all agencies that work in the creator space — in the last three years.

“There is seemingly a big opportunity for many of these companies in extending the reach of campaigns with paid media which the agency manages,” Brian Wieser, a media analyst, wrote in a recent note. He said Hershey, Colgate, Macy’s and Gap were among major advertisers that mentioned influencers on recent earnings calls.

Coco Bassey, a fashion and lifestyle creator with around 338,000 Instagram followers, said she, too, had paid her own way to attend the ad festival in Cannes. On Wednesday, she met with marketers for Ciroc, the vodka brand, and joined a lunch for creators that Meta, the owner of Instagram and Facebook, hosted at the Hotel du Cap.

She likened her decision to go to Cannes to the time when, in her early years as an influencer, she and a creator friend paid their way to attend Fashion Week in New York and split a hotel room.

“I wasn’t even getting invited to shows, but it was coming out, showing up, meeting with brands,” Ms. Bassey, 37, said. In the last few years, she said, she has attended such events with sponsors like American Express.

Marketers are flocking to many creators whose end goal may no longer be “traditional fame.” Adam Waheed, a 32-year-old comedian who posts as @adamw, said that because his videos got two billion views per month across platforms, “it’s almost a step backward to do an ‘S.N.L.’” Outside of his videos, he has been performing stand-up with mentors including Kevin Hart and working on a movie that he plans to release exclusively on YouTube.

“There’s always been this pressure of like, ‘Oh, you built this audience — take them to Netflix,” he said. “Why can’t I just have them right here?”

TikTok sponsored Mr. Waheed’s trip, but said he would have flown himself out anyway because of the value in mingling with marketers. He hopes to start landing seven-figure advertising deals soon.

“Everything’s six figures,” he said of his deals now. That is a far cry from where he started, he noted. “At one point, I would do something for a free hat!”