In digital advertising, data is what fuels targeting, personalization, and performance. But not all data is the same. Marketers often work with three types: first-party, second-party, and third-party data. Understanding the differences—and how to use them—can make a big impact on how well campaigns perform, especially at the local or regional level.

What Is First-Party Data?

First-party data is information a company collects directly from its own sources. This includes things like:

• Website activity (pages viewed, time on site)
• App usage (features accessed, device type)
• Customer transactions (purchase history, product preferences)
• CRM data (emails, sign-ups, account details)

Because this data is collected directly from users interacting with your brand, it’s typically the most accurate, reliable, and relevant. You know where it came from and can tie it back to real behavior.

In a GEO context, first-party data might include things like the ZIP codes where purchases happen, the cities where users are most active, or the times of day people in certain areas are most engaged. This makes it easy to personalize campaigns by region or optimize media spend by market.

What Is Second-Party Data?

Second-party data is someone else’s first-party data that you gain access to—usually through a strategic partnership. For example:

• A hotel chain may share booking data with a travel site
• A retail brand may share loyalty data with a payment app
• A streaming service may partner with a smart TV manufacturer

This type of data is often shared under a commercial agreement and tends to be high quality, because it’s collected directly by the partner. It’s useful for extending your reach to new audiences that resemble your own customers.

Second-party data also supports localized strategies. If you’re running a co-branded campaign or activating in a specific region, partners with strong presence in that market can help you build more precise targeting segments.

What Is Third-Party Data?

Third-party data is collected by companies that don’t have a direct relationship with the user. These companies gather information from a wide range of sources—like websites, apps, surveys, and offline records—and package it for resale.

Examples include:

• Demographic databases
• Behavioral segments (e.g., “luxury shoppers,” “home improvement intenders”)
• Market research firms and data aggregators

Third-party data has historically been a key part of programmatic advertising, especially for scaling campaigns or targeting hard-to-reach audiences. But it can be less accurate and less privacy-compliant, especially with recent changes in tracking policies and regulations.

In localized advertising, third-party data can help fill in the gaps. If your first-party data is strong in urban markets but limited in rural areas, third-party segments can help round out your targeting.

Why This Matters

First-party data is quickly becoming the foundation of modern advertising. As cookies phase out and privacy regulations tighten, marketers are shifting toward data they control. It’s more sustainable, more compliant, and generally delivers better performance.

That said, second- and third-party data still have value—especially when building broader audience strategies or filling in missing coverage across geographic areas.

If you're running campaigns by market, region, or ZIP code, understanding the source and quality of your data is key. GEO-specific targeting only works if your data is accurate. Using the right combination of first-, second-, and third-party sources can help you reach the right audience in the right place at the right time.

Sam Khoury

Founder, Cedar Consultants

Creative consulting solutions for Adtech