According to a recently published patent spotted by CB Insights, Walmart "describes a system of connected sensors that could monitor customers' product consumption," reports The Verge. "The sensors would be attached to products and rely on a variety of technology, like radio frequencies, Bluetooth, conventional barcodes, and RFID tags." From the report: Walmart doesn't suggest that any one sensor type would work best; rather, it lays out its options. Apparently it has a lot of ideas: these tags would all track how often a product is used and where it's located in a home. They could also help Walmart figure out what other products it could market to users based off their purchases. A tag reader installed on a fridge, for example, could scan every item that goes inside. This reader could then track when food is going bad or needs to be reordered. On the other hand, an RFID system could figure out when a person is picking up their toothbrush and use that information to estimate how much toothpaste is left. It could then be automatically reordered.