First-Party vs. Third-Party Data: What You Own vs. What You Rent

While every marketing team is familiar with the phrase “first-party data,” the term can refer to many things; it’s used interchangeably for everything from tracking cookies to privacy concerns. The true meaning of the term, though, describes the information your team owns. Whether or not you have ownership of the data determines whether your targeting gives you an edge over your competitors. This guide covers first-party, second-party, and third-party data: who collects it, who can use it, and the best use case for each type.

First-Party vs. Third-Party Data: Key Differences

What Is First-Party Data?

First-party data is information you collect through your own systems from your own audiences. You control consent and how it’s collected, which gives you the advantage of understanding the data’s origins. First-party data is the most trusted data in your stack, but it does have some limitations.

Where First-Party Data Comes From

First-party data is collected from properties you own. For example, someone visits your website or buys a product. You control how you collect data, so you can go beyond contact information to learn how they’re navigating your site and what they’re purchasing and returning. Your CRM holds this data, but you can further gain information through loyalty programs and logged-in accounts. Layer information from customer surveys and preference centers on top of that, and you can build a complete profile to use for advertising.

Why It Performs

When you collect first-party data, you’re getting it directly from the customer. That makes it accurate, timely, and clearly permissioned. Since you’re working from your own information, you can see in real time what customers are doing and adjust your strategies accordingly. You can also request consent before the information is gathered, which ensures that every customer has opted in to receive your brand messaging. As privacy laws tighten, that historical record of consent will become even more valuable.

Where First-Party Data Runs Out

Relying solely on first-party data can limit your reach. The data stops at your own front door and arrives fragmented, split across phones, laptops, and logged-out sessions that can misidentify single customers as multiple people. Assembling all of that information into individual customer profiles can bring a new set of challenges.

What Is Third-Party Data?

Third-party data refers to information collected by providers that have no direct relationship with the end user. Data vendors gather their information from a range of sources and divide it into audience segments. Next, they license this data to advertisers for a fee. Third-party vendors give advertisers a level of reach they couldn’t achieve if they relied solely on their own data. The downside is a lack of visibility into where the data came from and whether customers consented when it was shared.

How Third-Party Data Is Sourced and Licensed

Third-party data providers gather information from pooled, unrelated feeds, including publisher networks, apps, and surveys. The data is combined and organized, then sold as a product. Pricing is typically based on the niche and how fresh the segment is. Without knowing how the information was collected, you can still buy a list of consumers who have shown an interest in, e.g., buying a car or taking a vacation. While this approach can extend your reach, it lacks transparency. In fields with more privacy restrictions, such as finance and healthcare, this can be a problem.

The Shared-Segment Problem

The biggest issue with third-party data is the lack of exclusivity. If you can purchase a niche list of customers interested in your services or products, your competitors can, too. When two advertisers arrive with the same customer list, the advantage shifts to whichever company bids higher. You end up paying extra to reach customers who are also being targeted by your competitors.

Where Second-Party Data Fits

Second-party data is information collected by someone else and then provided to you under an agreement. For example, you may share similar audiences with a business; under an agreement, you exchange lists. In some cases, one company grants another access to a database. These are typically complementary businesses rather than competitors; a gym might exchange information with a healthy meal prep service, e.g., or a hotel brand might swap lists with a car rental provider. Agreements can be structured to ensure both parties disclose how information is collected and whether consent was given.

The value of second-party data lies in the partnership. When agreements are exclusive and well-matched, they can give you a real edge, but a partner that shares the same information with multiple companies offers little more than you’d get by purchasing a third-party list.

Cookies vs. Data: Why the Distinction Matters

Cookies and data tend to be treated as the same thing, but this is far from true. A cookie is a small text file that helps a site recognize a specific browser session; it’s the technology that allows you to stay logged in as you move from one webpage to another. Data, on the other hand, is the information you collect from a visitor, including contact details and browsing and purchase history. If someone deletes a cookie, you lose that specific connection to their browser activity, but the underlying question of who owns your audience data doesn’t change.

This distinction is important because cookie-based tracking has been shaky for years:

• Safari and Firefox already block third-party cookies by default.
• Chrome and Edge give users built-in controls to limit or disable third-party tracking.
• Google had plans to shut off third-party cookies but reversed that decision, per Forrester, ultimately opting for built-in controls to let users manage the process.

The above restrictions primarily focus on third-party cookies, rather than your own first-party data. Cookie or no cookie, though, third-party audiences remain accessible to any competitor willing to pay for them, while you own your first-party data because you collected it. That’s why it’s always best to build a strategy around the data you own.

Rented Data vs. Owned Data: The Question That Decides Performance

When it comes to campaign performance, what really matters is whether you own the data, or you rent it from an outside provider. For platforms, “owned” refers to the first-party relationships with publishers and users that allow an entity to collect information directly from them. The alternative is a “licensed” agreement, which means the platform purchases information from audience segments that are available to every other advertiser. If a platform relies on licensed data, it can easily struggle with differentiation, as other buyers may be targeting the same customer pool with competing products or services. A platform that owns its data can offer the exclusivity that helps advertisers remain competitive.

Identifiers are an important part of the discussion, since platforms can only act on owned data if they can recognize one user across multiple devices and sessions. While some matches use deterministic matching and rely on a confirmed signal like a logged-in email, often, matches are based on probability. That logged-in email can also help advertisers recognize users across platforms using hashed emails that disguise the information.

All of this combined is why many performance marketers now look beyond first-party and third-party data for a full strategy. Eyal Pincu, VP of product, new ventures, at Realize, explains the pressure today’s advertisers face.

“Advertisers repeatedly face the same dilemma: Search and social channels deliver results, but the path is getting steeper,” Pincu explains. “Costs are skyrocketing, and creative fatigue is a persistent challenge, causing advertisers to reach the point of diminishing returns faster than ever. The bottom line is that advertisers want — and need — a performance channel that can deliver measurable results at a scale that drives significant, near-term, needle-moving growth for their business.”

How to Build a First-Party Data Strategy

The good news is that you can start building your own data strategy today. This list can help you get started.

1. Prioritize consent: Privacy laws are always evolving; the more you can do to prove compliance, the better. A consent management system can help you capture, store, and carry out your user opt-in choices, but make sure your solution covers GDPR, CCPA, and other privacy laws already in place.
2. Invest in data connection infrastructure: Successful first-party data collection relies on clean capture, safe storage, and customer connections. Look for a platform that efficiently combines records while also providing solid analytics.
3. Build a real value exchange: The most valuable data often comes from motivating customers to provide it. Exclusive offers and giveaways can jumpstart your first-party data collection efforts.

The last step is crucial, as Bennett Barrier, CEO of DFW Turf Solutions in Dallas, explains.

“This is what small businesses are not hearing nearly enough: The best first-party data does not come from cookie consent pop-up banners,” says Barrier. “It comes from people opting in and sharing their data through loyalty programs, special content, or interactive activities. And it’s worth it: An Econsultancy study indicated that companies using first-party data for personalization nearly doubled their conversion rates compared to more generic user journeys.”

That advice holds across every data-gathering effort. When users willingly provide information, you get more valuable data and, in return, better results.

Key Takeaways

The distinction between owning or renting your data is the most important distinction when you’re creating and carrying out a data strategy. First-party data brings accuracy and permissioning, but it limits you to those who have already interacted with your brand. Third-party segments offer the broadest reach, but they reduce your competitive edge because anyone can purchase the same data. Owning the data is only part of the job, though: you’ll also need to match scattered signals to the correct users, and that can mean the difference between holding raw signals and owning data you can act on.

Frequently Asked Questions (FAQs)

Is first-party data enough on its own?

On its own, first-party data is useful, but it’s bounded. You’ll be limited to the information you gather from customers using your properties, and one user’s interactions can be scattered across multiple devices. To get reach from your first-party data, you’ll need systems that can gather those fragments into one clear picture of each user. However, it’s still important to find new customers. Think of first-party data as the foundation, not the entire structure.

Is third-party data going away?

No. Despite the headlines about cookie deprecation, third-party data is here to stay. Purchasing information from vendors still has a place in the market because it allows brands to broaden their audiences. Savvy advertisers will layer this approach with first-party strategies, using third-party data for prospecting while also recognizing that relying on it reduces their competitive edge. This is why ownership, not availability, is the true differentiator in advertising.

Which is better for performance campaigns?

For performance campaigns, first-party data is better for accuracy and immediacy, while third-party data excels when it comes to raw reach. The exclusivity you get from your first-party data keeps campaign costs low, but when you need to scale quickly, third-party data is the best choice. The strongest strategies combine both types of data by building a foundation with first-party data and adding purchased reach only when it can earn back the extra cost. In the end, the best strategy is the one that rests heavily on data your competitors can’t buy.