HEM, MAID, and IP Addresses: How Reliable Are They?

With the impending demise of third-party cookies, advertisers are considering a few alternatives, such as first-party data and identity graphs, to deliver personalized ads to customers. As part of these efforts, advertisers are currently relying on three major identifiers — hashed email addresses (HEMs), Mobile Ad-ID (MAID), and IP addresses. These identifiers are crucial for first-party data collection and creating identity graphs.

But how reliable are these identifiers? MediaWallah recently conducted a study to identify these identifiers’ stability and accuracy. The study also attempted to provide the advantages and limitations of using these identifiers. A key finding from the study was that each identifier comes with its unique challenge. Further, it requires technology and expertise to leverage these identifiers. 

The following are the findings in detail.

See more: FLoC Paused: Google Postpones Removal of Third-Party Cookies on Chrome to 2023

HEMs: Poor Infrastructure Creates Unnecessary Loss

Hashed email addresses are high-value. At the same time, they need structure across the industry. HEMs are often handled poorly, resulting in mismatches. If the hashes are not done correctly, the data sets do not match together accurately. This leads to HEM mismatches. The average mismatch observed by the study regarding HEMs was 6%, which means a significant number of HEMs are not used despite being good IDs. And this presents challenges to scale. 

Bad HEMs occur because publishers and data providers are not meticulous about technical procedures. 

Pros

• They are consented, which means it is a privacy-compliant mechanism
• They are persistent: An email does not change once it is created
• They are tied to a person
• They are platform-independent. They can be leveraged for targeting across customer touchpoints.

Cons

• They are low scale
• They are expensive to collect
• They require privacy regulation compliance
• Errors from data suppliers may lead to incorrect hashing, rendering them unusable

MAIDs: Easy To Collect But Decreasing Longevity

MAIDs are the ID of choice for small screens but have low persistence. According to the study, when comparing Mobile Ad-IDs to other identifiers, the number of MAIDs per HEM had increased over time. In 2020, there were two MAIDs per HEM, and in 2021, there were 6 MAIDs per HEM. This implies that the median lifespan of MAIDs has reduced from 1.5 years to six months. The primary reasons for the reducing lifespan of MAIDs are:

• Users manually resetting their MAID, and 
• App or a session-based ID being confused with MAIDs, leading to increased numbers.

This amplifies the complexity of data graphing that is required to target a customer accurately. 

Pros

• MAIDs are easily accessible and can be integrated into adtech platforms
• They are good for targeting people through mobile apps
• They can be considered more persistent than third-party cookies
• Rich data is tied to user devices, which means better targeting and attribution

Cons

• They are limited to the mobile app environment for their activation
• There is decreasing persistence created by platforms like iOS, making it easier to block
• Similar to third-party cookies, MAIDs will be phased away on iOS platforms
• It is dependent on big tech decisions for its viability
• There are file delivery issues

IP Addresses: Highly Reliable but Need Technical Expertise

The study found that IP addresses are highly reliable IDs even for connected TVs (CTVs). However, 18% are not tied to a home, which is needed to differentiate for ad targeting. IP addresses also need technical expertise to distinguish between one-to-one and one-to-many instances to create an accurate ID graph that connects different channels, connects users to a home, and increases scale.

Moreover, about 25% of IP addresses change location in a 2-year period. Of the IP addresses that changed their locations, more than 33% spent fewer than three months in a single place.

Pros

• It allows passive and discreet collection similar to third-party cookies and MAIDs
• It can be tied to a location that is possibly a home, which is valuable for CTV
• It can link individuals or identifiers together that are in the same location
• The data can be used everywhere

Cons 

• It is less persistent
• On its own, it is difficult to identify if it is a home IP. Additional signals will be needed
• For individual-level targeting, IP would be more probabilistic than deterministic
• Platforms like Apple are trying to obfuscate it in the future
• It is not a consented ID like HEM

See more: Death of Cookies: It’s Time for First-party Data To Shine

How Businesses Can Prioritize the Identifiers Helpful for Them

Advertisers and businesses can consider investing more in email due to consent and persistence. They should also consider investing less in MAIDs due to deprecation, less reliability, and possibly less viability in the future. They can work with a partner who understands IP addresses, as these IDs are valuable if advertisers can differentiate between home and public IDs.

Conclusion

As seen from the study, all identifiers have their advantages and limitations. As such, none of them is a home run. While it may be easier to collect an ID, it may be less persistent. On the other hand, errors can reduce the value of an identifier. It is clear that ID collection needs technology and expertise to reduce errors and increase scale. But more importantly, businesses must invest in smart ID management and not focus on data collection alone.

Which of these identifiers do you rely on and how are you making sure their limitations do not affect your targeting? Let us know on FacebookOpens a new window , TwitterOpens a new window , and LinkedInOpens a new window .

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