You have probably seen some ads with QR codes. They want you to scan the code to get more information. In Japan, they are using more advanced method with NFC technology. Users only need to tap with their NFC-enabled phones to know more.
As you can see in the above photo, the agency has embedded the NFC chip in the subway strips. After you use the phone to tap on it, your phone will direct to the advertisement website.
Many smartphones start to support NFC, so this seems a clever method to deliver advertising messages.