Click here if you have previously opted out and want to opt in.</li> </ul> <p>To opt-out on mobile devices and mobile apps, see Mobile Advertising Identifiers below or refer to Information on Opting out on Mobile Devices at NAI site.</p> </li> <li>Mobile Advertising Identifiers<br> Mobile device system software offered by companies such as Apple and Google provide device-based opt out choices that are transmitted to companies providing interest based advertising on mobile devices, which is sometimes referred to as cross-app advertising.