GAID: What is a Google advertising ID?

The Google advertising ID is a device identifier for advertisers that allows them to measure user ad activity on Android devices. It has often also been called the Android advertising ID, but Google advertising ID (short form: GAID) is more commonly used.

The most important thing to know about the GAID is that it will soon not exist anymore, thanks to Google’s plans for Privacy Sandbox on Android.

Web marketers can think of the GAID or Android advertising ID as somewhat analogous to a third-party cookie on the web.

Advertisers use third-party cookies to know what actions a user of a particular web browser is taking on their ads on various websites. The Google advertising ID does something similar: it helps advertisers know when an ad has been viewed or clicked in an app, and when a mobile ad causes a conversion. An app install would be a common tracked conversion using the Google Advertising ID. So would a purchase or other post-install in-app event.

The GAID or Android advertising ID is a hot topic right now because it will most likely not exist after 2024. Apple did something similar in iOS 14.5, making the IDFA — the iOS version of Google’s advertising identifier — opt-in on a per-app basis, which increases privacy but also reduces advertising effectiveness, particularly in targeting, and almost completely eliminates retargeting.

The IDFA still exists today, but according to Google’s plans, the GAID will not.

In its place Google will offer Privacy Sandbox on Android, which will offer methods for sandboxing SDKs in SDK Runtime, targeting ads in Topics API, audiences and remarketing (the Protected Audiences API, formerly known as FLEDGE), and attribution reporting via the Attribution Reporting API.

History of the GAID, or Android advertising ID

Naturally, advertisers want to be able to connect ad views with actions in order to determine return on ad spend, or ROAS.

Before mobile became the dominant means of accessing the internet, cookies served that function in desktop web browsers. Marketers could set a cookie on a website or in an ad and then measure ad effectiveness. But cookies don’t work well in the mobile world: they work in web browsers, not mobile apps, and we tend to spend most of our time on our phones in apps, not mobile browsers.

Plus, cookies typically have short life spans… somewhere around one to thirty days.

So the GAID or Android advertising ID took the place of cookies in mobile advertising delivered to Android devices, just as the IDFA did that on iOS devices. Marketers have used it to connect app installs or purchases to specific anonymous individuals.

The good thing about GAID from a marketers’ perspective is that in contrast to cookies, Google advertising IDs are semi-permanent device identifiers because they don’t change unless users specifically take an action in their Android device settings. Because few consumers actually do take this action (fewer than 5% in the U.S.), Android advertising IDs can offer a better foundation for a persistent and anonymized consumer profile based at least in part on ad interaction data.

Privacy and GAID (and IDFA)

Privacy has become increasingly important for consumers, and therefore for large platforms like iOS and Android.

Misuse of advertising identifiers and trackers have created significant problems, and legislation like GDPR and CCPA (the California Consumer Privacy Act) have limited how marketers can collect and use data. The major platforms, starting with Apple, have moved to decrease the amount of data that can be collected digitally from consumers.

Now Google is doing the same with GAID, the Google Ad ID.

Interestingly, both the Android advertising ID and the IDFA were actually privacy-focused identifiers.

Each are temporary and changeable device IDs that replaced a permanent device ID, the Android ID or ANDI on Android, and the Unique Device Identifier or UDID on iOS. Before Google created the advertising ID, advertisers could track activity on Android phones using that permanent and unchangeable device ID. The Android advertising ID enabled more consumer choice and privacy because people could turn it off or change its value – neither of which was possible with permanent device IDs.

Even so, there is increasing concern that advertising identifiers like GAID and IDFA can also cause significant privacy violations.

That has led Apple to make IDFA opt-in with ATT, or App Tracking Transparency, and offer SKAdNetwork as a privacy-safe replacement. Google will be replacing the GAIDs functions in ad measurement and mobile attribution with Privacy Sandbox on Android. In addition, the Google Play Install Referrer acts just like a referrer on the web, helping marketers know where an install came from while masking the specific identity of a person installing a device.

Using the GAID or Android Advertising ID (for now!)

When consumers take actions because of ads, like clicking on a banner in an app, playing a video in an app, or installing an app, ad networks can provide the Android advertising ID with information about the consumer action that took place because of the advertising.

This is still possible today, and will be until Google deprecates the GAID in 2024 or thereafter. It’s called attribution, and it attributes actions, or conversions, to stimuli, or ads.

Most media companies do pass Android advertising IDs.

Some media companies, including some large social networks like Meta, do not pass device IDs to advertisers but do allow you to target specific IDs within their properties. Singular helps advertisers by associating in-app consumer actions and marketing programs to these semi-permanent identifiers. This helps advertisers understand the effectiveness of their marketing and create powerful customer profiles to understand their audiences.

Using Android advertising IDs and app attribution tools like those offered as part of the Singular Platform, marketers can understand which ads, creative, campaigns, and media partners were responsible for the consumer conversions they want. Using these insights, they can calculate the ROI for all of their ads and tactics, and optimize their campaigns and ads to the most profit-generating tools.

The Android Advertiser ID also enables a marketer to target specific individuals that have taken actions in the past on their mobile devices or find others such as the most highly-engaged users in their apps.

For example:

• Re-engagement
  • Find people who have installed an Android app and deliver advertising that invites them to relaunch the app
  • Create an audience of lapsed users and advertise to them on their Android phones to get them to come back to the app
• Offers
  • Identify people who have abandoned items in shopping carts, and present an offer for them to come back and complete their purchases
• Look-alike audiences
  • Identify devices from users who are deeply engaged and profitable in your app, and ask an ad network or media company to find more people who look like those, and therefore would conceivably be good new users to acquire

This sort of individual targeting has become increasingly common as programmatic media and social media advertising grow in popularity for the marketing of apps. However, they are no longer possible in most cases on iOS due to ATT and the IDFA becoming opt-in, and will become harder to achieve on Android as the GAID becomes deprecated.

Most of the functionality of the Google Ad ID will be replaced by Privacy Sandbox on Android, though it won’t be as long-lived, fine-grained, or powerful.