If you wish to limit behaviorally targeted advertising, you can do so by limiting ad tracking in your device settings. Please note that opt-outs are specific to each device and it may take a little bit of time before your opt-out will take effect.
For mobile advertising in apps, you can reset your Advertising Identifier and depending on your device, select to opt out of interest-based ads (Android) or turn on the Limit Ad Tracking setting (iOS). Settings vary from device to device but you will usually find the ad identifier settings under “privacy” or “ads” in your device’s settings.