What is first-party data?
First-party data is information you collect directly from your own audience on your own properties: site behaviour, purchases, support conversations, and anything customers tell you. You own it, you know how it was gathered, and you can use it without depending on another company's identifiers or another company's consent.
Compared
First, second, third and zero-party data Four labels that get used loosely. The distinction that matters is who collected it and what relationship justified the collection.
| Type | Collected by | Example | Durability |
|---|---|---|---|
| Zero-party | The customer, deliberately | A preference they set, a survey answer, a how-did-you-hear-about-us field | High, and explicitly consented |
| First-party | You, on your own properties | Pageviews, purchases, support tickets, email engagement | High, under your control |
| Second-party | A partner, shared with you | Co-marketing lists, a partner's audience data | Depends entirely on the partner's terms |
| Third-party | A data broker, aggregated | Bought audience segments, cross-site behavioural profiles | Low, and collapsing with third-party cookies |
Why it became the default strategy
Three forces converged, and none of them are reversing.
- Third-party cookies were restricted or removed across browsers, which broke the cross-site identity graph that third-party data depended on.
- GDPR, CCPA and their successors made the provenance of purchased data a liability rather than a detail. You have to be able to say where it came from.
- Consent rates on real banners are far from universal, so any strategy that only works for consenting visitors is working on a biased slice of the audience.
First-party data is unaffected by all three, because it comes from a direct relationship rather than from an intermediary. That is the whole argument, and it is a durable one.
Owning it means more than collecting it
You can export it
If the data is only useful inside one vendor's dashboard, it is their asset with your name on it. Full CSV and JSON export is the test.
You know its provenance
Every field should trace back to an action someone took on your property. That is what makes it defensible in a data protection review.
It is not silently resold
Some free analytics is paid for with your visitors' data feeding an advertising graph. Read what the vendor does with what you send them.
It survives a vendor change
Ownership means being able to leave. If switching tools means starting your history from zero, you did not own the history.
Live demo
See it on real data. The live demo is a fully populated dashboard on demo traffic, with no signup and no card.
Open the live demoFirst-party analytics in practice
Analytics is usually the largest first-party dataset a company has, and often the least well treated: collected through a third-party script, stored in someone else's warehouse, and locked into one reporting UI.
Serving the tracker and the collection endpoint from your own domain changes that in two ways. Requests are first-party, so adblockers and browser policies do not remove them, and the data path is yours end to end rather than routed through a third-party host.
mrkr supports that with a managed first-party proxy: a neutral subdomain of your own domain handles the tracker and ingest, so there is no third-party hostname for a blocklist to match.
Where mrkr stands
mrkr collects first-party data only. It never builds a cross-site profile, never sells or shares what it collects, and in the default cookieless mode it stores nothing persistent on the visitor's device to collect it.
Your data can be exported as CSV or JSON, including raw events, so leaving is possible and history is portable. Be aware of the gap between that and the marketing version of data ownership: there is no self-serve export button in the dashboard yet, so today an export means asking us for one.
Where you need identity that persists across sessions, the optional per-site cookie mode provides it and requires consent on that site, and your own authenticated user id remains the most accurate route for logged-in products.
FAQ
What is the difference between first-party and third-party data?
First-party data is collected by you, from your own audience, on properties you control. Third-party data is collected by someone else, aggregated across sites, and sold on. The difference matters for accuracy, for legal defensibility, and increasingly for whether the data exists at all.
Is first-party data affected by cookie restrictions?
Less, but not immune. First-party cookies still work, though Safari caps script-set ones to seven days. Analytics that avoids browser storage entirely, or that serves from your own domain, is affected least.
Is zero-party data just first-party data?
It is a subset with a useful distinction: zero-party data is what customers deliberately tell you, such as a preference or a survey answer, rather than what you observed. It is the most reliable data you can hold and the only kind that sees channels analytics cannot, such as a podcast mention.
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