Rihanna’s celebrity is powerful for fashion brands.

The singer’s first limited-edition collection with premium footwear brand Manolo Blahnik launches today in three of the brand’s stores. The collection, titled “Denim Desserts,” includes different styles of heels all made out of denim; the star of the six-piece group is a pair of denim stiletto thigh highs topped with a bejeweled garter. For $3,500, customers can dress like Rihanna.

That is, only if they can get a hand on them. In addition to being sold in just three of its stores, the shoes went up for special order on Wednesday, one day ahead of the in-store launch. Each online pair is made-to-order, and won’t be delivered until October 2016.

Manolo Blahnik is a new fish in the waters of e-commerce, having just launched its own online store at the end of March. The site is powered by online luxury marketplace Farfetch’s commerce platform, for which Manolo Blahnik is the first brand partner to launch. The excitement around the Rihanna x Manolo collection caused the new site to buckle: On Wednesday morning, trying to reach the site resulted in 504 errors.

One day to go… #DenimDesserts launches tomorrow in Hong Kong, London and New York @badgalriri #RihannaxManolo

A video posted by Manolo Blahnik (@manoloblahnikhq) on

For a high-end fashion brand that’s late to the e-commerce game, a well-timed celebrity collaboration is a smart way to draw in customers.

“Today, luxury brands have to up their game — and the definition of luxury is changing. Having incredibly curated celebrity collections in a digital setting is a fabulous tool,” said Melanie McShane, head of strategy at Wolff Olins.

Rihanna’s fashion career so far has been a demonstration that everything she touches will immediately sell out. Her New York Fashion Week debut in September 2015 for her Fenty collaboration with Puma was the most discussed show on social media, with 35,000 mentions. The second-most mentioned show, Tommy Hilfiger’s, had 14,000. The items in the collection sold out as they were available in September.

“Rihanna is a gamechanger,” said Adam Petrick, Puma’s global director of brand and marketing. “Her attributes align with our brand, and consumers are more design savvy and tuned in to that than ever.”

Outside of the brands that Rihanna partners with, her touch has resulted in a halo effect for related retailers. To be worn with her Puma slide ons, the singer partnered with accessory company Stance for a collection of Fenty socks the sell for between $16 and $20 a pair. Her Fenty cosmetics line, made with LVMH’s Kendo beauty division, is on its way after the company signed the signer with a $10 million deal.

Get the #AnkleBrat from my #RihannaXStance summer collection!

A photo posted by badgalriri (@badgalriri) on

When the singer paid a nod to collaboration partner Manolo Blahnik in her video for “Kiss It Better,” released April 1, by wearing a pair of the designer’s Pitina heeled sandals. The shoes sold out online at Saks, Bergdorf Goodman and Neiman Marcus shortly after. Similar retailers have shared the excitement for the upcoming Rihanna x Manolo collection on Instagram in order to ride the coattails of the buzz, even though they’re not selling the goods themselves. Her collaboration hashtags — #RihannaFenty, #RihannaxManolo, #RihannaxPuma and #RihannaxStance — have cumulated around 360,000 Instagram mentions.

“With Rihanna’s fan base, she pushes the word out there further,” said Kellan Terry, a data analyst at Brandwatch. “Celebrities’ fan armies have a willingness to follow their lead, and Rihanna’s collection with Puma has performed so well because of it.”