In a mobile marketing context, a device ID is used by marketers to track app installs and provide users with ad personalizations. Because device IDs are unique to each mobile device and are stored within, the ID can be retrieved by any app installed on the respective device.
Traditionally, a device ID is a hardware identifier (SSAID for Android) used to distinguish devices for technical purposes. However, it could also identify users, which is why advertising IDs were introduced to be used separately for marketing measurement as well as give users more control of their data privacy. Advertising IDs do not contain any personally identifiable information such as name, address, and phone number. Today, these two terms are used interchangeably.
In recent years, there has been a major shift in user privacy regulations from user-level data to aggregate data. More specifically, Apple’s introduction of the App Tracking Transparency (ATT) framework (since iOS 14.5) has impacted how app owners can collect user-level data, including device ID-based data. Now, app owners have to request permission to gain access to a user’s device ID and track their in-app activity.
Apple’s iOS uses device IDs called Identifier for Advertising (IDFA), which is made up of a combination of 8 digits, a dash, followed by three sets of 4 digits, all in uppercase (ex. EA7583CD-A667-48BC-B806-42ECB2B48606).
Before the launch of iOS 14.5 and ATT, users were opted in by default, sharing this ID with app owners. As mentioned above, users are now automatically opted out of this procedure, and marketers can only gain access to this information upon the user’s decision to allow data tracking.
Android’s device ID is called Google Advertising ID (GAID), and it uses the same format as IDFAs but is presented in lowercase (ex. 38400000-8cf0-11bd-b23e-10b96e40000d).
Similar to Apple’s recent user privacy initiative, in June of 2021, Google released a new function in Android 12 that gives users the ability to opt out of ad personalizations. The IDs of opted-out users are shown in a string of zeroes to app owners, unable for personal tracking.
To further address rising privacy concerns, Google recently rolled out a new marketing measurement solution in beta called the Privacy Sandbox for Android, along with plans to deprecate GAID. The Privacy Sandbox aims to strengthen user privacy by eliminating the use of cross-app identifiers like GAID and limiting data sharing with third parties, but it still has the ability to collect key marketing performance data.
In mobile marketing, device IDs can be used to identify users and attribute each of them to user behaviors. It is a handy tool for evaluating an app’s marketing performance from the pre-install to post-install stage.
Specifically, with device IDs, marketers can easily segment their users based on certain identifiers like device type, geographical location, and usage patterns. Grouping users that share similar characteristics allows for a better comparison of user behaviors and determining marketing events that work best for each.
This data can also be aggregated to see big-picture overviews of an ad campaign’s performance as well as to spot trends and common occurrences in user behavior.
It is important to note that segmentation is limited to opted-in user data only, and the available data may not be representative of all users. Since marketers do not have access to the device IDs of opted-out users, they may be missing out on big chunks of data that could be valuable input.