The image of US President Barack Obama and First Lady Michelle embracing each other after he won the presidential election has become the most re-tweeted photo in history.
The photo, which was taken after Obama won the election, was re-tweeted 815,824 times and made a favourite 297,755 times by Twitter users.
However, along with the photograph, it is Michelle's 86-dollar dress in the picture that is making news.
The dress, by ASOS, Britain's largest online-only fashion and beauty store, sold out the first time Michelle wore it, and the retailer has not been able to meet demand since then, reports the Sydney Morning Herald.
ASOS has 2.1 million likes on its Facebook page, 411,000 Twitter followers and 315,000 followers on Instagram, and whenever a dress such as Michelle's chic red and white checkered print dress is put on social media it is an instant sell-out.
Prue Thomas, an ASOS marketing manager, said social media had become a powerful tool and major commercial opportunity for the fashion industry.
"As soon as [as a celebrity] tweets a picture of themselves wearing a dress, there is a huge spike in sales and it instantly sells out. Everyone wants their hands on that item. That one shot of Michelle is fashion gold for us," Thomas said.
Facebook is the No.1 social media sales driver, she said, but the photo-sharing tool Instagram is on the rise.
Camilla Freeman-Topper of Camilla and Marc said social media was an "incredible direct link" to their customers.
"Editorial in magazines takes a while for the effect to trickle through [to customers] while having social media has immediate, direct effect. Everyone who follows you, wants to follow you. We have a media person full-time looking after our social media, constantly answering inquiries," Freeman-Topper said. (ANI)