Spitballing here, but I'm pretty sure stores maintain a local database of their product prices in order to attach them to POSes. My knowledge may be outdated wi

Spitballing here, but I'm pretty sure stores maintain a local database of their product prices in order to attach them to POSes. My knowledge may be outdated with the advent of things like Square, though... But it seems to me that, given the fact the stores in the article were the ones supporting the move, that this would be a viable way to track and display price changes over time independent of information manufacturers control. It wouldn't do to pull data from a hostile source.