https://support.google.com/google-ads/answer/2453995?hl=en "Device location: Depending on a user's location settings, we may be able to use a precise location for advertising, based on one of these sources of location data:
GPS: Accuracy varies depending on GPS signal and connection. Wi-Fi: Accuracy should be similar to the access range of a typical Wi-Fi router. Bluetooth: If Bluetooth and/or Bluetooth scanning are enabled on a device, a publicly broadcast Bluetooth signal can provide an accurate indication of location Google's cell ID (cell tower) location database: Used in the absence of Wi-Fi or GPS. Accuracy is dependent on how many cell towers are located within an area and available data, and some devices don't support cell ID location."
Geo IP data is accurate ~85% at the city level and ~99% at the state level, meaning they're approximately the same.
- they don't get your location if you don't click on the ad. Since people don't click on ads very often, only rarely does an advertisers get a person's location, and without a name attached.
- Mobile phone companies were letting people query a user's location based on their real name. How would you do that with advertising?
We need to move beyond one-bit thinking. Location-revealing services aren't all the same.