M&S had been forced out of France in 2005, having become an unprofitable destination for English curiosities like jam and crumpets.

But M&S was planning a second French conquest, launching a new e-commerce platform and opening a flagship store in the Champs d'Elysees in the heart of Paris.

The ambition was to become a viable destination for dames de la mode with an eye-catching new fashion collection.

Who were we planning to speak to? Parisiennes in their 20s - the most stylish and discerning fashionistas on the planet?

So no pressure then. Good.

To give them credit, M&S had pulled off something a bit special: gorgeous cashmeres, cuddly-yet-sassy woollies, breathtaking boots, and even the occasional all-eyes-on-MOI statement piece.

So we decided to put the clothes in a Facebook app you could go into and browse like a virtual wardrobe, and then unleash chaos.

Because once inside, you discovered you could have any of these pieces for free, including limited edition designer collaborations.

But first you had to post it to your wall and BEG your friends to Like it - up to 30 Likes for a few limited designer pieces. To generate extra panic, we helpfully included a time limit of an hour.

The campaign went viral and had to be ended (a little embarrassingly) after just 4 hours, with M&S running out of stock.