The white T-shirt is one of fashion‘s most crowded categories and one of the hardest to get right. For Sold Out NYC, breaking through that noise has translated into real numbers.
So far in 2026, the brand’s sales are up 80 percent year-to-date, building on a record November 2025, when sales rose 100 percent year-over-year — the brand’s strongest month at the time. The white T-shirt alone brought a comparable lift, cementing its place as the label’s most reordered and viral product. For founder and CEO Kiane von Mueffling, the numbers are the output of a marketing and product strategy she’s been refining since launch.
Von Mueffling, who came to fashion from a finance background, frames the growth as the result of several channels working in tandem rather than any single lever. “All channels were firing,” she said, pointing to paid social, affiliate partnerships and wholesale as parallel growth drivers rather than competing priorities.
Meta Ads remains central to the brand’s paid strategy, but von Mueffling is explicit about its ceiling. “Meta has limits. Anyone who tries to exclusively scale on Meta, they’ll do well out of the gate, but eventually has a natural limit where the performance will start to wane,” she said. “You can’t use that alone.”
One adjustment inside that channel did move the needle: putting von Mueffling herself in ads rather than relying solely on polished editorial content. She said founder-led creative nearly doubled return on ad spend, which she attributes to authenticity, with customers seeing the person who designed and built the product, rather than a styled campaign image.
Affiliate marketing took longer to click. Sold Out NYC had tried the channel before without traction, but a shift to a fully commission-based structure changed that. “We’re happy to pay strongly on commissions. If you can sell for us, we want to partner with you,” von Mueffling said, describing the relationships less as influencer deals and more as ongoing partnerships with creators who use and believe in the product. Wholesale expanded alongside it, adding a third growth channel to the marketing mix.
Behind the channel strategy is what von Mueffling calls analytical rigor, a close, continuous monitoring of what’s converting and adjusting spend accordingly. The brand also took a category risk in 2025: after soft-launching knitwear in the fourth quarter of 2024, it committed real inventory to the category the following year. The bet paid off, pushing Sold Out NYC, previously built around tanks, T, and woven shirts, into a year-round assortment.
Still, the core of the business remains the basics, a category that is hard to sell, according to Von Mueffling. “A white T, a white T — the competition could not be fiercer for this product,” she said. “It’s very easy to get someone dressed in a huge, interesting color. That’s easy to sell. A white T, basics, are harder to sell than anything.”
Von Mueffling described scrutinizing every proportion, neckline and fabric choice before a style goes to market, then continuing to revise it afterward. “Customers these days are unbelievably savvy, and they should be,” she said. “They will not give you a second shot. You have to live up to the hype.” She also draws a firm line on quality versus cost, saying she has killed products in development when the only way to hit a price target was to cut corners she wasn’t willing to cut.
The brand’s customer, according to von Mueffling, is 25 to 55 years old, with the heaviest concentration between 35 and 55. She describes the appeal as fewer, more reliable pieces rather than a closet full of options. “That’s really the new luxury,” she said. “Not having too much stuff, but instead having things in your wardrobe you can absolutely rely on.”
Looking ahead, von Mueffling said growth has accelerated further in 2026 and that expansion will stay close to the brand’s existing categories, building out knitwear, pants and dresses, with collaborations expected over the next 12 months.
