A South Korean grocery chain has launched "virtual grocery stores" which let customers buy groceries simply by scanning a code on a poster in the subway. Because what could be a more appetizing place to purchase food than the subway?

Here's how Home Plus—the North Korean version of the British chain Tesco—did this, from to the Technology Review:

In a trial run, Home Plus has plastered a subway station with facsimiles of groceries, labeled with a unique code for each product. As commuters pass by on their way to work, they can use a mobile-phone app to take pictures of the products they want, then check out. The groceries are automatically delivered to their doorstep by the end of the work day.

According to the Tech Review, this has boosted sales by 130 percent. It does sound very convenient, if gross. But maybe they have much cleaner subways in South Korea than in New York? Or much filthier grocery stores?