Addressability Expansion

Addressability expansion appends additional identifiers to existing records in your identity graph to improve match rates in downstream activation platforms. Unlike graph enrichment, which changes the graph’s structure by adding edges between nodes, addressability expansion adds more “handles” to existing nodes—giving activation platforms more ways to find your customers.

What addressability expansion is

Every activation platform has its own identifier ecosystem. The Trade Desk works with UID2 and MAIDs. Meta matches on hashed emails and phone numbers. CTV platforms use device-level identifiers. If your CRM only contains email addresses, your match rate on a MAID-based platform will be low—not because your targeting is wrong, but because you lack the right identifiers to reach your audience there. Addressability expansion solves this by appending additional identifier types to your existing records. A customer who was previously reachable only via email becomes reachable via email, MAID, hashed phone, and postal address.

How it works

Consider a direct-to-consumer brand with a CRM containing one email per customer. Their current match rates:

Platform	Identifier accepted	Match rate
Meta	Hashed email	62%
The Trade Desk	UID2, MAID	15%
CTV platforms	MAID, IP address	8%

After addressability expansion with a provider that appends MAIDs, hashed phones, and additional email addresses:

Platform	Identifiers available	Match rate
Meta	Hashed email + hashed phone	78%
The Trade Desk	UID2 + MAID	51%
CTV platforms	MAID + IP address	34%

The brand’s audience segments did not change. The same customers are targeted with the same logic. But those customers are now reachable on more platforms.

What it does NOT do

Addressability expansion has clear boundaries:

Does not change segmentation. Your audience definitions stay the same. If a customer was in a segment before expansion, they remain in it. If they were not, expansion does not add them.
Does not improve targeting quality. You are reaching the same people with the same intent. The improvement is in reach, not precision.
Does not resolve identity. Expansion does not merge separate profiles or discover that two records are the same person. That is graph enrichment.

The value of addressability expansion is straightforward: higher match rates on activation platforms, which means more of your intended audience actually sees your campaigns.

What to look for in providers

When evaluating addressability expansion providers, focus on activation outcomes:

Criterion	What to measure	Why it matters
Identifier coverage by type	Volume of MAIDs, hashed emails, hashed phones, etc.	Determines which platforms benefit from expansion
Match rate lift by platform	Before/after match rates per destination	The direct measure of value
Freshness and churn rate	How recently identifiers were observed, how quickly they go stale	Stale identifiers waste spend on unreachable users
Identity type breadth	Person-level vs. household-level identifiers	Different activation strategies require different granularity
Cost per incremental match	Total cost divided by net new matched users	The efficiency metric for comparing providers