This week Pippa Middleton stepped out in a Hobbs NW3 Wyldes shift frock when she watched the tennis at Wimbledon.
And today Hobbs have now sold out of the bright orange £129 ($206) dress and bidding has gone crazy on eBay.
Earlier in the week, Pippa's older sister Kate Middelton, now better known as the Duchess of Cambridge, also attended Wimbledon.
She turned heads in a pleated £795 ($1,100) Temperley Moriah dress and within hours that too had sold out.
Dress designers and fashion houses across the world are now lining-up to offer their wares to the two sisters in the hope they may step out in one.
However, a source said: “Pippa and Kate outshine every other model on the planet at the moment – there is no-one to touch them.
“What is fabulous though is that so far they have bought their own stuff and gone for sensibly-priced stuff.
“But they still look absolutely amazing, which gives all us mere mortals hope.”