The Walmart of Korea, emart, devised a brilliant interactive marketing plan to draw in consumers during the slumping lunch hours. Essentially, they created a 3-D shadow QR code using the angle of the sun at noon. The shadows worked much like a sundial and on a sunny day the QR code would appear, when consumers scanned it, they would be offered special deals for a small online and store window of one hour. The campaign boosted sales during lunch by 25% and monthly membership by a whopping 58%. Well played emart of Korea, well played.