For an introduction to the main concepts involved in online advertising, see Introduction to Ad Serving.
Since mobile devices have become one of the primary ways people access the Internet, learning the basics of mobile buying is essential. The documentation in this section is designed to provide you with an understanding of how advertising works on mobile devices. If you're interested in a more technical explanation, AppNexus also provides a public MRAID and Mobile Video Tutorial intended for audiences who need to work with our mobile offerings.
Mobile advertising is very similar to web display advertising, with a few exceptions, which we'll discuss below.
There are two kinds of advertisements for mobile devices:
In mobile web advertising, users are typically targeted and success is typically measured in the same way as web display advertising. For in-app advertising, users are identified by their mobile device IDs. The device ID, as its name implies, identifies users for all applications on the mobile device, unlike cookies, which are specific to each website. Different operating systems use different identifiers: IDFA (iOS), AAID (Android), and Windows Advertising ID (Windows). These identifiers were created specifically to be used for advertising and provide users the ability to opt out of identification by resetting their identifiers. Identifiers are also reset if the operating system is reinstalled.
Note that the device ID cannot be linked to personally identifiable information (PII).
In addition to the typical kinds of segment or browser targeting, mobile devices can be targeted by:
Latitude and longitude, in particular, allow for precisely targeted advertising, such as advertisements from stores that are geographically close to the device user.
Currently, users cannot be reliably identified across multiple devices. This affects targeting and frequency capping. For example, if you see an ad multiple times from your Android phone and hit the frequency cap defined by the campaign serving that ad, you shouldn't see that ad anymore. If you switch to your iPad later in the evening for some bedtime reading, you won't be identified as the same user by the campaign, and you may see ads from that same campaign again. Frequency capping on mobile devices works on a per-device basis; in other words, if you switch devices, your frequency cap is reset.
As in web display advertising, it's difficult to identify users across different browsers on the same device. If the user switches mobile browsers, then frequency and recency will only apply on a per-browser basis.