First-Party Data Strategy: How to Advertise Without Losing the User's Respect

Data brokers, password leaks and spam calls – the average user knows their privacy is being screwed and they are NOT happy about it. The days of tossing user info around shady websites are going away, and so we, as marketers, have to change our approaches.

Meet first-party data – the supposed saviour of the advertising game. No more third-party vendors, only the data users agree to share on trusted websites. But is it really all sunshine and rainbows?

Why is simply "replacing third-party data with first-party data" not possible? What data types even are there, and why are they so different? How do you get first-party information, and how do you build a first-party data strategy?

No matter if you’re an advertiser or a publisher, let's find out all of these together!

What Is First-Party Data?

No messing around, let's get straight to the point.

First-party data is the type of data that you, as an advertiser or publisher, gather directly from your users or customers. Hence, it’s “first-party,” meaning it’s only shared between you and them.

Okay, but what exactly fits the description? In essence, every piece of data that you gather on your own platform through their interactions falls into this category. First-party data includes:

• Purchase history and shopping cart orders;
• Emails and phone numbers;
• Website online behaviour (time spent, language chosen, page visited etc.);
• Login data and IP;

What’s So Special about First-Party Data?

Let’s face it, the user experience without first-party cookies (blocks of data created by a website you’re visiting) is like pizza without sauce. You can eat the dough and ingredients, but will you get any enjoyment from the process without that layer of taste that makes it all work? Probably not.

Allegories aside, better UX is not the only thing making integrating first-party data so important. Namely, you can use first-party data advertising for a competitive edge, and that’s the whole focus of this article. First-party advertising is:

• Accurate (customer insights are gathered directly from them)
• Up-to-date (collection happens as soon as the user visits the website)
• Compliant with GDPR and CCPA (no third parties involved – no problems with the privacy regulations)
• Has better trust (the users like web privacy, no matter how vague the concept is)

From the user’s point of view, they know their data won’t end up in a spammer’s database.

From the publisher’s point of view, the content on their website or app begins to have more value as it attracts a bigger audience and higher-paying data.

From the advertiser’s pov, they get accurate data for effective advertising that also won’t get them in trouble.

We could write even more about the benefits of first-party advertising here, but our CSO, Andriy Liulko, has already covered them in a great way:

First-Party Data vs Second-Party Data vs Third-Party Data vs Zero-Party Data

Surprise-surprise, first parties aren’t the only ones who can collect information. In fact, there are plenty of data types.

Yes, they are quite different, yes, this is all quite confusing, and yes, you do need all of that knowledge if you want to create your first-party data strategy. So, let’s try to make some sense out of modern data collection.

What Is Second-Party Data?

Second-party data is someone else’s first-party data effectively shared with you via a direct partnership. You don’t buy it on the open market; it’s usually exchanged in strategic deals.

How does it work in real life?

Let’s imagine you run a travel site. You share your user data (e.g. “users browsing Rome trips”) with a hotel network. In exchange, they share their hotel-booking behavior. This is second-party because it's exclusive and consented, not sold alongside hundreds of other data segments.

So yeah, the important thing that makes second-party different is that although it’s shared with basically a third party, it still is secure and prestigious enough to be called that.

The pros are obvious:

• Everything that first-party data has to offer, but without the need to gather it yourself;

The cons are natural:

• This kind of relationship requires trusted partners and a lot of legal hassle to make it work;

What Is Third-Party Data?

Third-party data in advertising is like smoking in the 60s: everyone knows it's bad, but you can’t imagine the epoch without cigs.

And the ad tech has been trying to quit, that’s for sure. You’ve definitely heard about Google’s cookie scandal, and how the company delayed third-party cookie elimination three times just to cancel their decision.

So, what even is third-party data, and why do users dislike it?

Unlike first-party data, this one is aggregated and sold by brokers/aggregators who gather information across many sources with no direct relationship to the end user.

In short, when you enter a site that asks to enable cookies (explicit consent wasn't required in the past, btw), they can either belong to a first party (website owner) or a third party (sold across multiple sources).

The latter stinks for quite obvious reasons:

• Not secure for the user (data is tossed around the web in grey areas);
• Has low accuracy and data quality (the customer gets the ad for a toaster they searched 2 years ago for)
• Doesn’t support cross-device targeting (new device – new user, irrelevant ad as a result);

If third-party data is so cringe, why does most of the industry still rely on it? The reasons are as straightforward and predictable:

• It’s well-known and old (everyone knows how the whole thing works)
• It’s massive (deeply engrained in every advertising sphere)
• It’s cheap (who doesn’t like saving money at the expense of quality?)

What Is Zero-Party Data?

Zero-party data is even more precious than its first-party counterpart. Why? Because instead of simply collecting data, while the user silently consents, zero-party data is information that the user gives you voluntarily.

Let’s make it clearer:

Zero-party data is the information that customer intentionally shares with the brand to improve their experience.

Think of it as a deal:

• The user gives info on their preferences, purchase intentions, likes and dislikes, or how they want to be recognised;
• The brand gathers information and returns with relevant recommendations, ads, discounts, personalized offers, and unique website recognition;

Surely, zero-party data won’t solve world hunger or advertisers’ greed. A lot of customers will ignore it or give wrong answers to complete email and loyalty programs quickly, but the pros far outweigh the cons.

You have:

• Accuracy (far better than third-party, likely better than first/second)
• Cross-device targeting;
• Doesn’t require billions of dollars to generate, just be creative.

Actually, why don’t you just watch our related video, which explains zero-party in detail and with a portion of memes?

Where to Collect First-Party Data?

By now, we’ve established two main things:

• First-party data is great for all participants of advertising process;
• It belongs to an entity that collects it directly from its audience;

So, it’s the question of “Where to collect data?” for publishers and “Who owns it?” for advertisers. Let’s start with the former.

Publisher’s POV: How to Collect First-Party Data from Your Own Websites or Apps

Gathering first-party data is the publisher’s key to deep pockets and high demand. It’s not a piece of cake, and requires a mix of UX finesse, smart tech, and trust, but we believe in you.

The best collection channels for publishers include:

Websites & Mobile Apps

What to Collect: page views, session time, bounce rates, clicks, product views, time spent, items favorited, scroll depth.

Tip: Use Google Tag Manager, Firebase, Mixpanel, Segment.

Email Subscriptions & CRM Integration

What to collect: names, emails, behavioral patterns (open rates, CTR).

Tip: Use welcome flows to enrich profiles, retargeting, and upselling based on lifecycle or interest groups.

Offline Channels (In-Store, Events, Call Centers)

What to collect: Signups at events, POS systems, or inbound calls.

Tip: Use customer IDs (emails, phones) to link online & offline.

Advertiser’s POV: Where to Get First-Party Data

Things obviously get more complicated when you don’t own data and only have the option to buy it. At first glance, there appear to be five ways to gather first-party information.

Walled Gardens: Ease of Use over Freedom

Walled gardens like Meta, Google, Amazon, and TikTok offer massive volumes of logged-in user data. Basically, they build their multi-billion-dollar empires around the fact of ownership of such a valuable asset as first-party data.

Unmatched scale, powerful optimization, unique data, access to purchase and intent signals wrapped into a clean UI – naturally, most advertisers use their services.

There is a massive catch, however, you DON’T own this data. You can only target within their ecosystems, often with limited transparency. Plus, once you stop using the services of a walled garden, they simply take away your access.

What’s worse, walled gardens often provide no visibility into impression-level data or, even worse, distort the results, so the advertisers pay more than they actually have to.

Collect First-Party Data Directly

Technically, if you don’t like the limitations of walled gardens, nothing stops you from collecting first-party data yourself. Brands like you can build their own databases using:

• Landing page forms (newsletters, calculators, discounts)
• Customer purchases (in-store, online)
• App engagement (login behavior, in-app preferences)
• Customer support chats or CRMs

You control the data, store it, and reuse it across the platforms exactly how you want. Wonderful, isn’t it?

But unfortunately, this method is often simply insufficient.

• As a brand, you simply lack the scale of usable data that publishers can have.
• Moreover, data must be structured, clean, and privacy-compliant; otherwise, it’s useless.

Do you have the money, traffic, and resources to fix both of these? If so, good for you; most marketers don’t. Still, do you have the right tech to activate and scale it?

Without the correct software, even the cream of the crop data is useless, so don’t hesitate to use DSPs that won’t limit you in features and customization. Try a white-label solution that lets you brand a vendor’s platform as your own, like Epom DSP.

Partner with Publishers

Publishers or apps can share their valuable first-party data with advertisers for targeting purposes. Okay, technically, this is cheating because you get second-party data, but who cares?

The point is, you get highly relevant data without the limitations of walled gardens.

As for the cons, it’s the same for all second-party data: hard to find good sources + requires data-sharing agreements.

Data Clean Rooms

If you and a partner both have logged-in audiences, you can match anonymized data in a neutral environment, such as Google Ads Data Hub, Amazon Marketing Cloud, Snowflake, etc.

In essence, the companies that provide cloud storage act as intermediaries that match anonymized user profiles.

These environments are great for data attribution without compromises, but they are still quite underground in ad tech. Data clean rooms require technical expertise and are still the domain of their service providers. Honestly, they deserve their own article someday.

Data Co-Ops & Media Networks

Data cooperatives are places that aggregate first-party data from logged-in users and let you target them. The examples include services like Wiland, Alliant, or I-Behaviour.

“Wait, a minute, how is this different from a clean room?”

In short, data co-ops are more chill & open to strangers (like you) and less exclusive & closed than clean rooms. The point of clean rooms is privacy-safe data matching, while for co-ops, it’s data pooling to expand reach.

For instance, in clean rooms, data never leaves the environment (just like with walled gardens), while in co-ops it’s redistributed to members.

What’s Wrong with First-Party Data Advertising?

Before we move to the final piece of the pie, it’s time to address the point that has probably been on the tip of your tongue this whole time: “First-party data programmatic advertising is not perfect.”

• Inaccuracy

Every piece of info marked as “first-party data” shouldn’t become your Holy Grail. Depending on the source from which you gathered it, it’s often incomplete, inaccurate, or even outdated.

Over 41% of marketers say they struggle with data accuracy even in large companies. And that’s despite the fact that most brands spend at least 30% more on acquiring it.

• Insufficient Volume for Activation

Advertisers rarely leverage more than 47% of their first-party data’s potential. Particularly, smaller brands struggle to build usable audience segments, especially when working with restrictive walled gardens like Google and Meta.

• High Costs

First-party data is much harder to obtain than its third-party counterpart. Naturally, it’s much more expensive. Moreover, if you’re a giant advertiser, you’ll require a CDP to utilize this data effectively, and that also doesn’t come cheap.

The truth is – there’s not enough accessible first-party for everyone. Otherwise, we wouldn’t have any of these issues. Bear in mind that despite how great this type of information is, it’s not enough on its own.

How to Build a First-Party Strategy?

Honestly, by this point, you already know almost everything there is to know about first-party data. In this section, let’s quickly sum up all of the info in a step-by-step strategy.

Publishers, we’ve already shared everything we know with you. Gather data – sell data, there’s honestly not much else to it. Advertisers, you are welcome to continue reading.

Step # 1. Plan & Invest

Before collecting a single data point, define clear business objectives. What do you need? Lower customer acquisition cost? Better personalization? Behavioral insights? Without clear goals, data becomes noise.

Then map out:

• Required data types and volume (e.g., emails, behavior, purchases)
• Technology stack (tracking tech, CDP, consent tools)
• Budget estimate (CDP costs often range from $4,000–$12,500/month, plus staffing, plus data collection itself)

Tip: Include compliance upfront. GDPR and CCPA can be a money pit in the future, so you'd better get ready for audits.

Step # 2: Collect & Organise

You don’t need a CDP to get started. But you do need structure.

Collect data from sources we’ve discussed (walled gardens, your own resources, publisher relationships, data clean rooms, data coops). Then, organize it:

• Use whatever works: Google Sheets, CRM, Airtable, or SQL warehouse
• Segment by user behavior, engagement, and value
• Clean the data often — duplicates and empty fields will kill your strategy later

If you grow into needing a CDP or data warehouse, great. But start small and scale smart, then invest in additional technology.

Step # 3: Activation

This is where most strategies die — because collecting data is easy, but doing something with it? Not so much.

Here’s what activation looks like without a CDP:

• Export audience segments and upload them to Google Ads, Meta, or your Epom DSP
• Use email tools (like Klaviyo, Mailchimp, HubSpot) to trigger lifecycle flows
• Build custom landing pages based on user traits or marketing campaigns

Okay, but when to use data from each important channel? We’d sum it up like this:

Step # 4: Measure & Optimize

No data strategy works without feedback. You need to know what’s working and what’s noise.

• Track performance by audience segment (not just channel)
• Watch for fatigue — even great first-party data decays if overused
• Use A/B testing to validate the value of each data point or trigger

Step 5: Stay Compliant & Scale

As your data operation grows, so do the risks. Think ahead:

• Make sure every bit of data collected is clear and in compliance with the data privacy laws;
• Store all the data securely — even if it's “just” email lists or product views;
• Update your privacy policy and cookie banners regularly;
• Consider how you’ll scale: clean rooms, coops, or alliances with trusted publishers;
• Scale your marketing efforts effectively with the right DSP;

First-party data strategy is not a panacea, but in the right hands and with the right tech, it really is a game changer. We hope we helped you acquire the right knowledge and skills.

As for the tech, why not back up your decentralized and privacy-compliant advertising with a feature-rich programmatic platform like Epom white-label DSP? We are not an evil walled garden that limits your data usage – do whatever you want and scale your first-party data strategy according to your needs.

Still having doubts? Check out our demo.

FAQ

• How can customer feedback help improve my first-party data strategy?

  Customer feedback isn’t just for stroking egos or collecting complaints. It’s a goldmine of qualitative data that adds nuance to the raw numbers. By incorporating feedback forms, surveys, or support chats into your data collection, you can enhance your profiles with preferences and pain points. This is your fuel for better personalized experiences and smarter segmentation.

• What role do customer interactions play in collecting more first-party data?

  Every click, scroll, tap, or rage-quit is a data point. Mapping out customer interactions across your website or app gives you behavioral breadcrumbs, signals that help understand intent and drive retargeting. Think of it as following the user's digital footprints (minus the creepy stalker vibe).

• How do I manage user consent without scaring people off?

  Managing user consent shouldn’t feel like legal waterboarding. Make it clear, friendly, and optional. Use layered consent forms, clear cookie notices, and honest opt-ins. Bonus: users who say “yes” willingly are usually more engaged, making your data cleaner and your lawyers happier.

• How can analyzing customer behaviour lead to better targeting?

  Patterns in customer behaviour, like repeat visits, abandoned carts, or binge-reading your blog can be used to predict future behaviours. When you know what users are likely to do next, your targeted marketing campaigns stop feeling random and start feeling relevant.

• What’s the difference between user interactions and transactional data?

  User interactions are what people do, like browsing, clicking, and engaging. Transactional data is what they commit to, like purchases, sign-ups, or downloads. Combine the two, and you don’t just know what users like, you know what they’re willing to pay for. That’s the sweet spot for campaign ROI.

• Can personalized experiences really be built without third-party cookies?

  Yes, you can block third-party cookies and still build personalized experiences, as long as you're leveraging data directly from your own ecosystem. Use behavior, preferences, and consented identifiers (like email or phone) to tailor content. It’s more work, but at least the user won’t hate you.

• How can I collect user information without being invasive?

  Easy: earn it. Offer value like discounts, useful content, and early access, in exchange for info. Keep forms short and make disclosures transparent. This builds trust and opens the door to more first-party data without pushing users away.

• Are universal user IDs the future of the customer journey?

  Universal user IDs sound futuristic because they are, kind of. They help unify fragmented identities across devices and platforms without relying on third-party cookies. When done ethically and with proper consent, they’re powerful tools for improving the full customer journey, but right now, there’s no industry consensus toward using them.