Resetting Advertising ID - Apple iOS
You may reset your device’s Advertising Identifier, which will result in your device being disassociated from ad targeting profiles based on the Advertising Identifier in effect prior to reset. You can do this by clicking on Settings -> Privacy -> Advertising -> Reset Advertising Identifier.

Resetting Advertising ID - Google Android
You can reset your advertising ID by clicking the menu icon to display the apps list, then find and select the Google Settings icon, then find and select "Ads" and selecting "Reset advertising ID".