Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.

Meghan Markle won't technically become a royal until she walks down the aisle and says "I do" to Prince Harry on May 19, but she's already got the fashion gravitas of a full-fledged icon.

When Markle buys and wears something, people follow suit, and it's having lasting implications on the brands she chooses—especially the more niche ones.

Take, for example, one of Markle's latest outfits: the "Jackie O" black dress ($375; bloomingdales.com) from the brand Black Halo. The dress has been a favorite of stars like Blake Lively and Kim Kardashian West, but when InStyle asked a rep from the brand whether they saw an impact after Markle's recent outing, they confirmed that it indeed flew off the shelves after she wore it.

Meghan Markle lead

"The Classic Jackie O dress in black sold out in less than 10 hours, all the other colors are super low in stock," they said.

The London-based consulting business Brand Finance confirms as much. CEO David Haigh told WWD that the net present value to the brands Markle endorses is estimated to be $212.1 million.

“I think they appreciate that their patronage has a very significant economic effect," Haigh said. "I think it will be very consciously thought about. It will be very beneficial for the people they do it for.”

Having that kind of fashion influence makes the question of who will dress Markle for her wedding—the designer has been chosen already—an even bigger deal.

“It will be like winning the national lottery for whoever does it," Haigh said. "Every time she wears a coat, it goes online and sells out. When you see the coverage, it’s very interesting. It’s almost like a catalog. She appears somewhere, there are little arrows [near the photos] saying she got this coat here, it cost ‘X,’ these boots come from there—whatever, whatever.”

With only a month to go before the wedding, it won't be too long until fans see what she wears—and promptly follow suit.