New Look has sold out of a £29.99 dress worn by Holly Willoughby on This Morning yesterday.
While the presenter is often to be seen on the programme sporting designer ranges, she yesterday morning went for a High Street leopard-print skater dress instead, teamed with thick black tights and Prada shoes.
Holly shared a picture of the dress on Instagram, which won more than 19,000 likes - and women have been flocking to buy it for themselves. Within just a few hours, both the New Look website and eBay had sold out of the flattering animal-print number.
And Holly's Instagram followers say that in stores, too, the dress is nowhere to be found.
Duchess of Cambridge causes a run on a £17.50 dress
The 35-year-old presenter favours designers including Alexander McQueen, Roland Mouret and Prada. However, she frequently teams these items with high-street bargains from the likes of Topshop and Zara, inevitably prompting a shopping frenzy.
Earlier this year, for example, she caused a run on a £45 dress designed by Alexa Chung for Marks & Spencer.
With celebrities generally wearing clothes that are way out of most women's price range, any high-street items they pick tend to fly off the shelves. In one extraordinary example three years ago, pop star Rihanna triggered a frenzy over a pair of £12 jogging trousers from Tesco.
Rihanna causes a run on Tesco jogging trousers
But over the last few years, the phenomenon has become most widely associated with the Duchess of Cambridge - so much so that it's been dubbed the 'Kate effect'.
In 2012, for example, a £162.50 Orla Kiely dresscoat sold out 'within minutes' of her wearing it for a public appearance. A year later, she was spotted wearing a £17.50 maternity dress from Asos, prompting the retailer to reorder large quantities in new colours.
'Kate effect' boosts profits at Reiss
In 2010, the Reiss website actually crashed as shoppers flocked to buy the dress she'd worn for her official engagement photograph; the following year, the chain reported that its profits nearly doubled as a result.