While I've never used Freshdirect, I can't imagine it's quite as fast and easy to browse products there as it is to just visually scan across a huge wall of products. That's the advantage for the consumer.

The advantages are bigger for the seller. You don't have to rely on people remembering "Oh yes, I need to do some shopping" and going to your website. Instead they'll be walking through the subway station, remember "Oh yes, I need kim chee" and buy some. It's as good as having a store in the subway station, except that the store takes up no room and costs way less.

I can really see this store-on-a-wall thing taking off, and not just in Korea. If you can be the middleman who standardizes the protocol which lets anyone buy anything and get it delivered to their home, just by scanning a QR code, you'll make a lot of money.