Identity resolution is becoming standard practice for marketers. More than 90% of survey respondents use identifiers, and more than half (54.5%) say they sometimes, often, or almost always work with multiple third-party identifiers, according to a March 2026 survey of 112 US-based agency and marketing professionals by EMARKETER and Acxiom.

Eight in 10 respondents say identity resolution has improved marketing ROI.

• Personalization tops the list of benefits, with 40.2% reporting measurable gains, followed by attribution and measurement (32.1%) and media efficiency (28.6%).
• This helps explain why 60.7% of marketers expect to increase investment in identity resolution over the next two years.

Rather than investing in more disconnected tools, organizations are prioritizing initiatives that bring customer information together. The leading investment area is creating a unified customer view across business units (38.4%), followed by website personalization (31.3%), and in-house identity capabilities (29.5%).

That signals a broader shift in priorities: Identity is becoming less about acquiring more data and more about making existing data usable across the organization.

That evolution is reflected in how marketers identify customers today.

Email and hashed email remain the most common identifier, used by 65.2% of respondents. But they're rarely used alone.

• Organizations increasingly combine authenticated first-party IDs, device IDs, household IDs, and third-party identifiers to build a more complete picture of the customer.
• More than one-third (34.8%) of marketers say they now rely on a balanced mix of first- and third-party data across marketing and activation.

Because there is no longer a single identifier that can reliably recognize customers across every channel and device, the advantage lies in connecting multiple signals into a unified view. That's where many organizations are still struggling.

• More than half (55.4%) of respondents say their first-party data remains completely siloed or only partially connected across systems.
• A quarter admit their organization still lacks a formal identity strategy, while 42.0% describe their customer data foundation as immature.
• When asked what's limiting marketing performance today, fragmented and siloed data ranked above privacy concerns, anonymous user visibility, and slow access to insights.

This is why interoperability has become such an imperative for marketers.

Only 23% say their identity systems are fully interoperable, while nearly two-thirds (63.9%) rate their ability to connect interactions across identifiers as only "somewhat interoperable."

As organizations add more data sources, marketing platforms, retail media networks, and AI applications, simply collecting customer information is no longer enough. The underlying systems have to communicate with one another.

AI is raising the stakes even higher. More than a third (38.4%) of marketers say AI and advanced analytics initiatives are driving current identity investments, yet more than half (52.7%) acknowledge their data foundation isn't ready to support AI-driven marketing.

Marketers have entered a new phase of identity maturity. The industry's focus is shifting away from individual identifiers and toward the systems that connect them. Identity is becoming less of a point solution for personalization and more of an enterprise capability that supports measurement, privacy, AI, and customer experience.

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