Have you ever wondered why some online ads you see are targeted to your tastes and interests?

Have you ever wondered why some online ads you see are targeted to your tastes and interests?
Or how websites remember your preferences from visit-to-visit or device-to-device?
The answer may be in the “cookies” – or in other online tracking methods like device fingerprinting and cross-device tracking.

Device fingerprinting can track devices over time, based on your browser’s configurations and settings. Because each browser is unique, device fingerprinting can identify your device, without using cookies. Since device fingerprinting uses the characteristics of your browser configuration to track you, deleting cookies won’t help.

Device fingerprinting technologies are evolving and can be used to track you on all kinds of internet-connected devices that have browsers, such as smart phones, tablets, laptop and desktop computers.

When you access mobile applications, companies don’t have access to traditional browser cookies to track you over time. Instead, third party advertising and analytics companies use device identifiers — such as Apple iOS’s Identifiers for Advertisers (“IDFA”) and Google Android’s Advertising ID — to monitor the different applications used on a particular device.

You can reset the identifiers on your device in the device settings. iOS users can do this by following Settings > Privacy > Advertising > Reset Advertising Identifier. For Android, the path is Google settings > Ads > Reset advertising ID. This control works much like deleting cookies in a browser — the device is harder to associate with past activity, but tracking can start anew using the new advertising identifier.