Here in the UK, the department store John Lewis' Christmas advert is something of an annual cultural event. The commercials are renowned for telling touching, emotional stories centred around the spirit of Christmas giving - as well as signalling, for many, the start of the holiday shopping season. If you aren't familiar with any of the brand's Christmas campaigns, check out recent examples including 2013's Bear and the Hare and 2012's The Journey.

This year, I wanted to take a closer look at how John Lewis built and launched its biggest advertising campaign of the year. It was always going to be a talking point online but, in particular, I wanted to see how the brand utilised social media to maximise exposure for the ad, and start to turn fans and viewers into paying customers. What follows is the story of the run-up to and first 24 hours (and a bit) of John Lewis' Christmas 2014 advertising campaign on social media, with a list of early indicators of success and key takeways for all marketers at the end: