By Carlo Versano

Even for Kim Kardashian, the dress was striking.

The superstar turned heads and had social media abuzz when she wore a gravity-defying, cut-out gown from French designer Thierry Mugler's 1998 collection to the Hollywood Beauty Awards last weekend. But in the hours that followed the gown's debut, even the most well-heeled fans were unable to purchase one of their own.

A vintage piece, the outfit was quite literally one-of-a-kind.

Until Monday, at least. By evening, an identical replica of the dress was available on the website of Fashion Nova, the fast-fashion brand popular with Instagram influencers. Retail price: $50.

It sold out immediately.

The social media uproar that ensued was a glaring example of the delicate dance between influencers and fast-fashion brands that thrive on social media trends ー and the designers who are often caught in the middle.

Kardashian wasn't happy with Fashion Nova. She took to Twitter, telling her 60 million followers that she didn't endorse the company producing a knockoff:

"It's devastating to see these fashion companies rip off designs that have taken the blood, sweat, and tears of true designers who have put their all into their own original ideas," she tweeted. "I've watched these companies profit off of my husband's work for years and now that it's affecting designers who have been so generous to give me access to their beautiful works, I can no longer sit silent."

Kardashian made a point to say she doesn't work with Fashion Nova, a statement that caught the attention of Diet Prada, the de facto Instagram arbiters of such fashion disputes. Diet Prada posted a screenshot of a leaked Fashion Nova photoshoot under the file name "Kim dress" which showed a model posing in the dress ー four days before Kardashian presented it on the red carpet. The implication: Kardashian leaked the dress to Fashion Nova to give them time to produce a knock off and cash in on the buzz surrounding the look.

Fashion Nova shot back, saying in a statement:" Fashion Nova is an ultra-fast fashion brand that is capable of executing design within hours and believes in fairness in pricing ... we have not worked with Kim Kardashian-West directly on any of her projects but have been driven by her influential style."

Indeed, Fashion Nova's CEO, Richard Saghian, told WWD last year that the company built its supply chain so that it could have samples within 24 hours of an item being conceived. The company keeps models on-call at its L.A. headquarters for shoots and can have a new piece online and available in one to two weeks. That is a "truly wild" product delivery cycle, according to Kate Taylor, a lifestyle editor for Insider. She told Cheddar that influencers, high-fashion brands, and fast-fashion sites often have a symbiotic relationship. " They feed off each other," she said.

Influencers like Kardashian are able to further cement themselves as trendsetters, high-end brands get attention that make them more enviable to the buying public, and fast-fashion gets the traffic ー and the revenue.

It is further evidence of how the once-sacrosanct world of high fashion has changed in the social media era, where the currency is likes and re-grams, rather than glossy magazine spreads. And it cuts both ways. As discount brands borrow from luxury, luxury brands are also looking for opportunities to create viral moments and cash in on social media buzz. In 2017, luxury brand Balenciaga dressed its models walking Paris Fashion Week in platform Crocs ー the famously uncool rubber footwear of chefs and preschoolers. Those shoes came with a price tag of $850, slightly above the $35 cost of a regular pair. They sold out instantly.

For designers who don't appreciate their work being knocked off and monetized, their recourse is limited. Fashion is not subject to trademark protections like other forms of art or media, Taylor said. But if an influencer like Kardashian has a business relationship with a site like Fashion Nova that isn't disclosed, that could run afoul of FTC rules. Federal regulators have repeatedly warned social media influencers that they have to make it clear when they are being paid to endorse products.

For many, Kardashian's denials that she was in cahoots with Fashion Nova rang hollow. Many users on Twitter wondered what was wrong with delivering consumers pieces on trend at prices they could actually afford, while others mocked the star, who has made millions on her appearance for getting upset with others who have done the same. Further, Kardashian's half-sister Kylie Jenner has a relationship with Fashion Nova. Saghain, the CEO, once called a post in which Jenner is wearing a Fashion Nova outfit "better than any Super Bowl ad" and said it could singlehandedly drive $50,000 in sales.

Fashion Nova has made no secret of its reliance on social media heavyweights like the Kardashians to fuel its 600-piece a week collection, Taylor said. So long as it doesn't promote the actual names and likenesses of celebrities, which could violate "right of publicity" laws, the brand is probably in the clear to continue executing on its business model.

But it's a fine line, and one that other brands, like Missguided, may have crossed. On Wednesday, Kardashian's lawyers filed suit against that fast-fashion company for using Kardashian's name and photos without permission to promote their own line of copycat designs.

In a now-deleted post, Missguided promoted a replica of a gold dress Kardashian had shown off in a prior Instagram shot, and tagged the reality star: "@kimkardashian you've only got a few days before this drops online."

Meanwhile, the online drama continued to boost the "Kim dress," which is sold under the name "Winning Beauty Cut Out Gown" on the Fashion Nova website. As of Thursday afternoon, it remained sold out, with customers urged to sign up for a waiting list.