Collaborations as a marketing tool have drastically increased in the past two decades. Now, countless partnerships across streetwear, fashion, sportswear and pop culture are announced on a daily basis, creating near constant buzz. Despite their ubiquity, these co-branded endeavors remain a guaranteed way to generate press and raise public interest. These irregular—and often unpredictable—drops reshaped the market and most assuredly hurt the bottom line for diffusion brands. The most clear cut example is H&M. Its pioneering high-profile designer collaborations, including Comme des Garçons in 2008 and Maison Martin Margiela in 2012—who in fact has its own diffusion-line, MM6—proved designer fashion was available at a price point even lower than diffusion could offer. These releases were a game changer for fast fashion, and H&M’s competitors took notice and followed suit.

These collaborations are not limited to high fashion. Fear of God, for instance, created a de-facto diffusion line, Essentials (formerly F.O.G), made exclusively for PacSun. Rather than invest in creating lower tier product, designer Jerry Lorenzo largely leaves production up to PacSun, creating hype through limited availability and utilizing PacSun’s massive retail presence and distribution chain.

Footwear—the most cost-prohibitive category for many young designers—is now but another alternative to diffusion. Countless brands and designers, from Raf Simons to Acronym, now work with Vans, Nike, adidas and so forth on footwear that mirrors their brand's respective aesthetic without compromising their core product. Even if you can’t afford Alyx, for instance, an MMW x Nike training shirt or rubber-dipped Vans authentic is much more attainable. Through collaborating with retailers and sportswear companies—not to mention the wild success of premium merch—designers can now successfully offer items at diffusion prices without diluting brand image.

Rather than distinguish between mainline and lower tier product, luxury brands have embraced basics. Cheap to produce and distribute, the T-shirt has become a perfect entry level statement piece for luxury brands to sell en masse. While graphic T-shirts were traditionally the domain of streetwear, fashion designers have successfully adopted the item into their oeuvre. The most obvious example is Riccardo Tisci, whose graphic heavy essentials exploded in 2011—in large part fueled by Kanye and Jay-Z wearing his designs during the Watch the Throne tour. Seeing the two rap juggernauts wearing the $400 Givenchy T-shirts for months introduced an entirely new audience to high-fashion. Suddenly the Rottweiler and Birds of Paradise graphics were street favorites. Givenchy’s massive success paved the way for the rest of the industry, and today branded T-shirts, hoodies, hats and sneakers are a key part of many high fashion house’s seasonal offering.

Instead of impacting a brand’s reputation with a lower priced sub-line, selling less cost-prohibitive items allows a label to expand its clientele while boasting huge profit margins. Although spending thousands on a leather is unattainable for most, luxury houses discovered there are plenty willing to shell out hundreds for a T-shirt. Although the current market is bound to hit a saturation point—and the "T-shirt and sneaker" aesthetic will inevitably wane—for the immediate future branded T-shirts will continue to sell, offering an alternative to diffusion lines.

A major shift occurred when Hedi Slimane was appointed creative director of Yves Saint Laurent in 2012. His decision to drop the “Yves” name to re-brand the house as “Saint Laurent” was initially ill-received, prompting a public outcry. The reaction was short-lived, however, and the change did not dissuade consumers from buying into the new designs. Soon after, the newly dubbed Saint Laurent Paris was a blockbuster success. Luxury houses realized that in today’s market, modernity and relevance outweigh history, and wearability is a major factor in sales. The luxury market has shifted to protect mainline reputations by reducing distribution and focusing on the current market rather than long-forgotten histories. Rather than leverage legacy, these houses focus on how to sell clothes to the current consumer.

When it comes to actual product, brands have put a priority on maintaining luxury positioning through increasing prices, while introducing the aforementioned “affordable” categories to appeal to a wider audience. In our current market, diffusion lines may confuse consumers and actually hurt overall brand perception. This may explain why popular sub-lines like Raf by Raf and Marc by Marc have ceased production. By increasing price points and simultaneously offering additional points of entry for potential customers, a lower tiered line is seemingly irrelevant.

As the amount of information available online has grown exponentially, so has choice in the marketplace. Department stores, auction sites, e-commerce and curated brick and mortar boutiques all contribute to a hyper-competitive retail landscape. With increased consumer knowledge and choice, comes increased scrutiny. Speaking to Business of Fashion, Lydia King, a womenswear buyer at Selfridges, explains how consumers are no longer fooled by pale imitations of the real thing. “What is increasingly clear is that watered down versions of main lines no longer convince consumers to buy. Customers are aware if a diffusion brand doesn’t have integrity and the collection is just really a money earner on the side,” she said.

Competition from multiple fronts is squeezing out the need for diffusion lines. Mid-tier contemporary brands like Acne, 3.1 Phillip Lim and Alexander Wang are still aspirational to shoppers but are available well below the premium luxury price point. On the lower end of the market, the constant stream of fast fashion collaborations allows budget conscious consumers to purchase a “designer look” at a fraction of the cost.

Even brands that have chosen to keep their diffusion lines active are increasingly careful on how they position them in today’s market. Comme des Garçons—no stranger to adding sub-brands to its expansive universe—has always been fiercely protective of its reputation. Today’s climate is no different. “We never liked the idea of diffusion because it kind of waters things down. It dilutes the idea. When you think of every single diffusion line, the name is shorter: Ralph Lauren becomes RL, Donna Karan becomes DKNY. When we did a second line for Comme des Garçons we deliberately made the title longer—Comme des Garçons Comme des Garçons—because it wasn’t a diffusion line, it was an extension: the thing that comes off the real thing, so you keep the spirit. The concept behind it is not lesser than the first Comme des Garçons line,” said president Adrian Joffe.

As its prone to, Off-White has bucked the trend and actually added a diffusion line of sorts. Dubbed “For All,” the line is sold exclusively at Off-White stores, with a limited range that includes tees and hoodies ranging in price from $95-$170. However, as the line is only available at Off-White flagships and appears intermittently, it quickly sells out, thus never making its way to the discount rack at Marshall’s like Marc by Marc used to. Even though it's technically diffusion, “For All” plays the angle of ostensible inclusivity, albeit being inherently limited—similar to Lorenzo’s ESSENTIALS. While a number of brands still explore the diffusion strategy—Rick Owens DRKSHDW and 11 by Boris Bidjan Saberi are still going strong—they are clearly the exception rather than the rule.

According to Ruth Bernstein, chief strategic officer and co-founder of fashion and luxury agency Yard, “The diffusion line died with the decline of middle-tier fashion...in a retail climate where customers call the shots, there’s not much room for the lesser offshoot of a core brand to really thrive.” Bernstein makes a good point. In a fashion environment where authenticity—at least, perceived authenticity—is king, streetwear rules and luxury brands are relying on exclusivity more than ever, diffusion simply does not make sense. If a brand wants to expand its reach and cater to a wider audience, today it has so many options, so why would it offer second tier product, potentially compromising its image in the process? While it might be too early to write off diffusion lines entirely, there’s no denying that the entire concept is dated, if not obsolete.