With #Whatsonsky we demonstrated where the future of out-of-home advertising lies – taking advantage of consumer behaviour in a rapidly growing social-mobile world.The campaign was based on solid research that people often don’t plan their viewing before any given evening, and can be overwhelmed with the range of choice available when they finally get to their sofas after a hard day’s work. Armed with this insight, Jam launched a campaign to target these weary commuters when they were most captive – when they were idly waiting for their train home. We erected digital billboards in 16 key commuter stations at peak hometimes over two weeks across the UK. These billboards encouraged passers-by to Tweet using #WhatsOnSky for a personal recommendation of what to watch based on their personal Tweet history and to have their name up in lights on the billboard. Everyone who Tweeted in were entered into a draw to win free Sky TV for a year.To make it work we created a number of new pieces of kit - a unique back-end system that could track the hashtag, an interface that could allow quick moderation and response to tweets, and a link to JCDecaux’s own system to allow Tweets to be published to the billboards in near real-time.