Nice narrowcasting

I discovered Build, – graphic design and art direction, via Anamorphis. Their flickr conversations inspired me – they bring a whole new twist to the idea of narrowcasting. Could the main objective be to spread happiness or kindness? or make people take a little moment just to think, or smile. I know if I saw a screen at a train station which made me do any of those things, I would always remember it…and want to go back. I need to find out what the main goal of the narrowcasting is? To make people return to that train station, to improve the experience, to give them specific information?…or simply make their day a little brighter?