Attempting to fathom the inner workings of the subway is one of those things that just about any New Yorker can relate to: every straphanger eventually picks up on which trains are more frequent at which hours, platform and station layouts, transfer times, etc. Nevertheless, even a seasoned commuter is subject to the opaque and capricious—if not outright counterintuitive—ebb and flow of the transit system, and waiting on the platform becomes second nature. (The highly unpredictable nature of my closest trains is one of the many reasons I prefer cycling, weather permitting.)
Well, if Tesco's pilot program in Seoul provides a glimmer of hope for more productive downtime, not to mention one of the more practical applications of QR codes I've seen:
Basically, the backlit billboards emulate the aisles of Home Plus (the British grocer's Korean store), such that otherwise-idle commuters could shop using their smartphones, such that their groceries would arrive at their doorstep at the same time that they would.
Read more at the Fresh N Easy blog