For many urban commuters, grocery shopping is another chore to be shoehorned into an already busy day, taking up valuable time and creating a logistics nightmare on public transportation. Imagine the relief these shoppers would feel if they could just press a button and have their groceries magically appear.

Last year Tesco, the UK grocery retailer, made this a reality, using the walls of a subway station in South Korea to display photos of products for sale, with each item carrying a unique QR code. Shoppers could use an application on their smartphone to read the code and place the selected item in a virtual shopping cart for home delivery after work.

Suddenly, what was once wasted time waiting for a train had become the ultimate in ease and convenience. Tesco has now taken its commuter-friendly shopping wall into the UK. market, as has Ocado, an online retailer.