People counting is the oldest form of store analytics: sensors at the door count how many visitors come in, which gives footfall and, combined with the number of tickets, a store-level conversion rate. Common people counters include infrared beams, CCTV and 3D sensors.
Their limit is that they only count visitors at the entrance, so the purchasing journey inside the store is missed. Our article on the evolution of people counters compares it with the web: online businesses moved from simple hit counters to Google Analytics, created in 2005, which measures time on page, navigation patterns and conversion rate. Stores are going through the same shift.
Retail intelligence tools measure the complete trajectory of each customer anonymously and passively, without cameras or mobile apps. Shoppermotion counts traffic per trip in every zone, not just at the door, and tracks occupancy in real time, with email or SMS alerts when a capacity limit or density threshold is reached.
Measured constantly, full trajectories help predict out-of-stock shelves, evaluate main aisle performance and plan the checkout staff needed to keep waiting times short.