On what many predict will be the busiest online shopping weekend of the year, eBay has opened a pop-up shop in London’s Covent Garden to promote itself as a destination for Christmas shopping.

The shop doesn’t have any products on show, but instead uses QR codes and augmented reality to links shoppers to product pages on eBay.

The idea is partly to give inspiration for Christmas gifts, but also to showcase eBay’s broad range of mobile apps.

Ebay expects a third of Christmas purchases to be made through mobile this year, though the percentage is predicted to be even higher than that for fashion and homewares.

We’ve previously reported that the online retailer expects its m-commerce sales to exceed $10bn in 2012, a figure that was revised up from an initial estimate of $8bn.

Ebay predicts that Sunday will be the busiest online shopping day of 2012 and expects to receive around 6m visits to its website.

To put this in context, eBay normally receives around 17m unique visitors per month.

Head of buyer experience Carrie Bienkowski said the company didn’t want to do another actual shop, but still wanted to be in the heart of London’s shopping district.

Last year was more about showcasing the brands that we partner with, but this year we want to show people that they can shop anywhere, anyhow. It’s really about demoing the power of mobile.

There’s also a big emphasis on social shopping. On of the ‘zones’ includes a Twitter Barometer that displays the top 10 most popular gifts based on sentiment analysis from the social network.

Unsurprisingly Justin Bieber was atop the list this morning, with other items including the iPad, iPod and digital cameras. The idea is that shoppers then scan a QR code and buy the items on eBay.

Other zones in the pop-up shop include ‘Top Toys & Tech’ which uses AR to bring to life a number of toys and gadgets – including a Furby and Spiderman – and a fashion area that displays a live feed of Instagram images taken by eBay’s fashion bloggers.

Shoppers can also scan different winter fabrics using eBay’s fashion app, which pulls up product ideas using image recognition.

The pop-up shop is open for three days from now until Sunday, and eBay expects to welcome around 3,000 shoppers through its doors.