MNI Blog  /  3 minute read

What are Mobile Ad IDs, and Are They in Danger?

Discover the importance of Mobile Ad IDs (MAIDs) in advertising and how they can enhance targeting and personalization in the consumer journey. Learn best practices for utilizing MAIDs and respecting privacy.


By Janine PollackDirector of Content Marketing at MNI Targeted Media


What are Mobile Ad IDs, and Are They in Danger?

Marketers have been giving a lot of thought to the loss of third-party cookies, which means no cross-site tracking tied to a universal ID. Enter mobile advertising IDs (MAIDs), the universal mobile device identifier within mobile apps. The MAID is the same across apps on a mobile device and is shared with all apps by the operating system. Since the MAID is tied to an individual device’s operating system, it is uniquely suited to allow for data personalization on the cross-channel consumer journey. Considering how reliant consumers are on mobile devices, especially during the pandemic and stay-at-home orders, this is good news for marketers.



A Device ID is a string of numbers and letters that identifies every individual smartphone or tablet in the world. It’s stored on the mobile device and can be retrieved by any app that is downloaded and installed. Apps typically retrieve the ID for identification when talking to servers.

How are Mobile Device IDs Used in Advertising?

Mobile apps use mobile advertising IDs (MAIDs). MAID targeting offers marketers information on mobile location data. While being completely anonymous, and fully manageable by the user, it opens the doors for advertisers to understand the fragmented user journey. 

MAIDs are helpful in following a consumer's buying journey; however, unless they are attached to another piece of information, MAIDs can be limiting. For brands and marketers looking to tap into the power of MAIDs, consider these best practices: 

  • Tap into mobile location behavior data: MAIDs give marketers the ability to take advantage of privacy-compliant mobile location behavior data to improve personalization and targeting timing. As an example, location data can tell if a device is frequently at a supermarket, which indicates that person may be receptive to coupons and offers.

  • Tie in offline deterministic data: While adding location-behavior data linked to MAIDs will provide insights for personalization, it’s important to enrich MAIDs with offline deterministic data to round out the insights and anonymously deliver critical qualifiers such as age, gender, income, wealth, and lifestyle. In the example above, a marketer would have no way to know if the consumer is male or female, or shopping for one or a family, simply by using the location data tied to the MAID.
  • Respect privacy: It is imperative to ensure the data-linking process is done through privacy best practices to protect personally identifiable information. Also, be careful not to over-personalize outreaches, so your messaging doesn’t move into creepy territory (e.g., “I saw you were shopping at Wegman’s recently!”).

What is the Difference Between MAIDs and cookies?

There are a couple of differences between MAIDs and cookies worth noting. Perhaps most significantly is the simple fact that MAIDs live much longer than a cookie. Like a real cookie, digital cookies have a shelf life because they’re session-based, whereas a MAID lives longer because you don’t continuously log-in and out of a mobile device when using apps. This fundamental difference leads to a reliable data set that can successfully feed programmatic targeting campaigns.

Another important thing to note is that MAIDs meet various privacy rules & regulations (including GDPR) and make cross-matching easier. As it stands now, cookies are now able to be blocked on a browser level to protect the user’s privacy, whereas a MAID is the same for all apps on a device. This makes cross-matching between partners easier and the marketing message much more precise. Overall, MAIDs solidify the importance of mobile as an integral targeting device.

Seize the Mobile Data Using MAIDs

Some brands also rely on innovative technologies to help enhance the data from MAIDs. For example, many now use an identity resolution platform to power a brand's own identity graph to link consumer data, such as names, addresses, phone numbers, etc., to help identify consumers and their profiles and attributes. If you use a third-party identity resolution provider, ensure it uses rigorous privacy processes and permissible content from reliable sources to comply with all federal and state data privacy laws.

With each new customer interaction, a customer’s profile continues to evolve and grow, so critical identifiers, hashed emails and other anonymous identifiers enable marketers to recognize customers across all touch points in a singular view. This power enables marketers to track changing buying patterns, gain deeper insights into consumer interests, and personalize the consumer experience in a privacy-compliant manner.

For Marketers, Every Moment Is an Opportunity—Identity Is More Than a Cookie or ID

If brand messaging is seamless and frictionless and brand messaging on point, consumers will be willing to receive it. The challenges and opportunities presented by cookies and MAID are for marketers to figure out behind-the-scenes as we head into the future of advertising.