Kate Middleton Wears a Navy Shift Dress, Crashes a Website

The Duchess of Cambridge attends a charity event. Photo: Getty Images

The Duchess of Cambridge has kept a low profile since her big New York trip, but on Thursday, the 33-year-old stepped out to perform some royal duties. Though the mod dress with patterned trim is very different from her usual look, the Kate Middleton Effect was in full force: the dress she’s wearing above is already sold out.

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Middleton, who is currently about six months pregnant with her second child, was on hand at Barlby Primary School to christen their new art classroom as part of her responsibilities as royal patron of the Art Room, a U.K.-based charity that aims to provide art as therapy to young students. She wore the Naomi dress by Madderson London that features patterned pink tweed panels on the pockets and hemline. The outfit has proven so popular that thousands of people attempted to log on to the British maternity line’s website and crashed it (you can buy it on a different e-commerce site for ￡450.00 or about $690). She paired the piece with opaque black tights and her go-to Stuart Weitzman heels.

Many items Middleton has worn in the past have also immediately sold out. A yellow Roksanda Ilincic dress she wore in Australia, a Tory Burch bouclé coat worn in New York, a $35 Zara necklace worn to a black tie event, are just some examples of the fashion power of the princess.

Related: Why You Should Shop Your Closet Like Kate Middleton

Now, following the #katemiddletoneffect will be even easier, thanks to the fact that the royals have joined Instagram and Twitter. Ladies, get your credit card and social feeds ready for the Duchess’s next outing.