If your wifi is on, cities are not the only people tracking your location. It's a huge industry - Euclid Analytics, Cisco, and others are providing stores with a customer's path, dwell times, etc. Connecting your MAC to your person is trivial with more than one visit to a store in which you pay with a credit card.

It should be noted that iOS 8 randomizes the MAC address during wifi probes, so with iOS 8 you will not be trackable unless you install the store's app.