Netflix is trying to turn its hit Squid Game series into a fashion hit too. Earlier this week, the streaming giant added Squid Game apparel—T-shirts and hoodies—to its fledgling Netflix online store.

But Netflix has a battle on its hands competing with unofficial fan products flooding Amazon, Etsy, and eBay. For the company, it’s a lesson learned: Selling meme merchandise can be difficult.

Squid Game, a survival thriller from South Korea, became the No. 1 Netflix series in the U.S. on Sept. 21, just four days after its global release. It took Netflix two weeks to start selling series-related goods, by which time the show’s iconic green tracksuits had already flooded the Internet.

Launched this past summer, Netflix’s store features a few dozen items—some customizable—based on hits like Lupin, Stranger Things, The Witcher, Sex Education, anime titles like Eden and Yasuke, and now Squid Game. But prices are anything but mass market. T-shirts sell for $35, hoodies $50, baseball caps $60, and shorts for a whopping $70. There are also toys and jewelry selling for $135, and a limited-edition collectible statue for $250.

Netflix first ventured into merchandising in 2017 through a licensing deal with Target to sell Stranger Things goods tied to the Halloween premiere of the science-fiction horror series. Then, last year, the company recruited Josh Simon from Nike to become its first vice president of consumer products. Simon grew his team from 20 to 60 employees, hiring away talent from Disney, Mattel, and Sanrio, and struck licensing deals with other retailers including Walmart and Sephora. In June 2021 he launched Netflix’s U.S. e-commerce shop, which Netflix told Fortune it plans to expand abroad.

Although it has added 10 Squid Game T-shirts and hoodies—more items than any other franchise in the shop—there are no Halloween costumes available on the site. Netflix has confirmed with Fortune that it has no plans to add any new Squid Game merchandise to its store in the next three weeks. But Halloween costumes inspired by Squid Game, such as those green tracksuits, are in growing demand, according to Google Trends, which tracks search interest in particular topics over time. Unofficial online merchants selling through Amazon and elsewhere are trying to meet the demand.

Under pressure from investors because of slowing subscriber growth, Netflix is looking to expand into new businesses. It has already announced a push into mobile gaming, which would be included in streaming subscriptions and is currently being tested in Poland. But it’s unclear how serious the company is about selling products based on its shows directly to consumers online, which other movie studios like Disney have turned into big money. For now, it’s just an experiment for Netflix.

Later this year, during the holiday season, Netflix plans a number of blockbuster releases like Red Notice, starring Hollywood heavyweights Ryan Reynolds, Gal Gadot, and Dwayne “The Rock” Johnson. There’s no word yet on whether Netflix will sell merchandise to go with its big budget releases.

As for the unauthorized Squid Game merchandise available, well, that may not be for too long. In the past few days, Amazon, for one, has started to take down at least some of those items.