Speculation but they could geofence individual home addresses and stores and generate a list of customers/employees, use the phone locations at 3am to get home

Speculation but they could geofence individual home addresses and stores and generate a list of customers/employees, use the phone locations at 3am to get home addresses and the location during business hours to predict whether (say) Walmart traffic was up or down vs Target. They could also figure out who works at Walmart/Target and track shift hours, headcount etc. and predict earnings.