Luxury labels demonstrated the instant selling power of social media during London Fashion Week like never before with videos broadcast live online to the world from shows crammed with tweeting, blogging designers, editors and celebrities.

Retail clothing chain Topshop reached the largest online audience for a live-streamed London fashion show on Sunday, with two million viewers tuning in from more than 100 countries to see Topshop Unique's latest collection.

According to figures compiled by the retail chain, more than 200 million people were exposed to images and content from the runway as part of Topshop's partnership with Facebook, where fans were led to Topshop's live-stream from their shopping site.

Most importantly, Topshop were able to see a direct impact from their social media coverage as people streaming online were able to immediately purchase the looks on the runway. Numerous items, including a dress that was the first outfit on the catwalk, sold out even before the show was over.

"People have been trying to figure out for some time, how do you make these 'likes' into something relevant, how does the social aspect mix with your brand, and I think we are going to be the first brand to unlock that, we're going to be the case study...(to) commercialize that social audience," Justin Cooke, Topshop's chief marketing officer, told Reuters.

In other efforts to embrace digital technology, House of Holland partnered with online bidding site eBay on a virtual pop-up shop and designer Alice Temperley showcased some of her recent Temperley London collections using "online runways".

"The traffic to the website kind of peaks when you tweet with Pinterest, Instagram," Temperley told Reuters. "It's just full-time work for a whole team of people, but it's the way things are going."

In addition to being an instant virtual shop, social media provides brands with a longer lasting forum for the online fashion communities keen to discuss every aspect of a collection, according to Lucy Yeomans, editor-in-chief of fashion retail site Net-A-Porter.com and former editor of UK's Harper's Bazaar.

"I think anyone who doesn't tap into the power of social media is just missing a massive trick, it's not just a marketing tool," Yeomans told Reuters.

EDITORS VS BLOGGERS

It's not just the brands that are using social media to connect with their consumers. Fashion editors have fought back against the fashion bloggers who briefly eclipsed their dominance on the front rows of the catwalks by jumping on the social media train with tweets, blogs and pictures of their own.

Magazine and newspaper editors have become social media celebrities in their own right -- Jo Elvin, editor of UK's Glamour Magazine, has more than 63,000 Twitter followers, while Joe Zee, creative director of US Elle Magazine, has 155,000.

Generally, a journalist's media coverage of a brand is still generally considered three times more powerful in value compared to advertising, as it gains an endorsement with an editorial story from the journalist, according to Katie Mitchell-Baxter, account manager at PR company Good Relations.

For fashion week alone, the British Fashion Council (BFC) estimates that more than 100 million pounds in orders are generated each season and that international media coverage was worth 61 million pounds.

Claudia Crow, creative director of boutique consultancy Talk PR, said that publications such as Vogue, Harper's Bazaar, The Telegraph and The Times are now at the forefront of reporting fashion news quickly, which was important for them in order to stay ahead of the competition from smaller outlets and bloggers.

"Journalists can make or break a line. If they write a good or a bad report, it's amazingly powerful, it's amazingly effective," Crow said.

(Editing by Paul Casciato)