Location smart SDKs, embedded into publisher apps, have transformed the way in which location data is obtained. It has allowed brands to extract pure, first party, data giving them access to the most accurate form of location data.
The location signals your device send say a lot about your behaviours and interests. Understanding a user’s behaviour based on the places they have been and routines they follow can be far more valuable to a brand than simply their online behaviour alone, helping advertisers move away from predefined demographic targeting and deliver relevant messages to audiences they know much more about
Source: Location data: How we got here | Mobile Marketing Magazine
Suggestion: If not using location services, disable it, at least when you do not need it. Turn off Wi-Fi when it is not needed, such as when walking in stores. Many stores now track your WiFi signal and its globally unique ID on the physical device. Yes, every network devices in the world has a globally unique ID and that is now used to track you and your devices.