Identity Graph
A database that maps and connects all known identifiers for a single person - such as email addresses, device IDs, cookie IDs, and phone numbers - into a unified profile that represents one real human.
Also known as: identity resolution graph, ID graph
Why It Matters
A single person might interact with your brand through a dozen different identifiers: a mobile device ID, a desktop cookie, a work email, a personal email, a social login, an in-store loyalty number, and more. Without an identity graph, that one person looks like a dozen different users in your analytics, inflating your user counts and fragmenting your data.
Identity graphs solve this by linking identifiers together based on deterministic matches (same login across devices) and probabilistic signals (same IP plus similar browsing patterns). The result is an accurate count of real people and complete cross-device, cross-channel profiles for each one.
For analytics accuracy, identity resolution is foundational. Conversion rates, retention rates, lifetime value calculations, and cohort analyses are all wrong if you are counting one person as multiple users. Getting identity right is the prerequisite for getting every downstream metric right.
Industry Applications
A multi-channel retailer builds an identity graph that links online customer IDs with in-store loyalty card numbers. They discover that their "online-only" customers actually make 30% of their purchases in stores, fundamentally changing the ROI calculation for their digital marketing spend.
A B2B platform uses an identity graph to connect individual user activity to company accounts. When three people from the same company are all using the free tier independently, the identity graph connects them, triggering an enterprise sales outreach that converts them to a team plan.
How to Track in KISSmetrics
KISSmetrics maintains an identity graph that links anonymous IDs, email addresses, and custom identifiers into unified person profiles. The alias method lets you explicitly connect identifiers when you know they belong to the same person. KISSmetrics automatically resolves identities across sessions and devices when a user authenticates.
Common Mistakes
- -Merging identifiers with low-confidence matches, which incorrectly combines profiles of different people
- -Not handling identity splits when shared devices cause two different people to be merged into one profile
- -Ignoring privacy regulations that restrict the combination of certain identifier types without consent
- -Assuming identity resolution is a solved problem - it requires ongoing maintenance as new identifiers and channels emerge
Pro Tips
- +Use deterministic matching (same authenticated login) as the backbone of your identity graph and add probabilistic matching cautiously
- +Implement quality checks that flag suspicious merges - like two profiles with different billing addresses or plan types being combined
- +Design your identity graph to handle splits (un-merging accidentally combined profiles) not just joins
- +Track your identity resolution rate (percentage of events tied to identified users) as a data quality metric
- +Consider the order of precedence when identifiers conflict - which source of truth wins?
Related Terms
User Alias
A method for linking multiple identifiers to the same person, such as connecting an anonymous cookie ID with an email address, or merging two separate accounts that belong to the same individual.
Anonymous User
A website or product visitor whose identity is unknown, typically tracked via a cookie or device identifier until they provide identifying information like an email address.
Identified User
A user whose identity is known through a unique identifier such as an email address, user ID, or account number, allowing their behavior to be tracked across sessions and devices.
Probabilistic Matching
An identity resolution technique that uses statistical methods to link identifiers that likely belong to the same person based on signals like IP address, device type, browser fingerprint, and behavioral patterns, rather than exact deterministic matches.
Customer Data Platform
A software system that collects, unifies, and activates customer data from multiple sources into persistent, unified customer profiles accessible to other systems for marketing, analytics, and personalization.
See Identity Graph in action
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