Price increases happen overnight, or with everything tracked and digitized, this could lead supermarkets to charge more money right when demand spikes or maybe in the future even target particular shoppers willing to pay more.
They're going to take your frequent shopper card and figure out what your price point for different goods are. Then they're going to take their tracking of your cellphone and figure out when you're approaching your favorite goods, to raise the price. The technology for everything part of this already exists and is being used, it's just a question of who links everything up first.