This "bump" technology is now fitted into credit cards.
You just wave your magic card near a traditional swipe machine and it subtracts funds from your bank account/creditcard account.
Do you remember Minority Report?
Technology is constantly scanning for eye prints and then trying to sell you shit as you're walking down the street, based on some public database defining who you are and how much money you have.
I asked a while back if the smart glass used in Minority Report was real or fake, since in the here and now it's actually real and commercially viable.