Glossary
What is zero-party data?
Zero-party data means details customers hand over on purpose, like stated preferences, rather than signals a business observes or infers.
Updated
Definition
Zero-party data is information a person intentionally and proactively shares with a business, such as preferences, purchase plans, sizes or communication choices. It differs from observed behaviour because the person chose to say it, usually expecting a better experience in return.
Stated versus observed
Behavioural records show what someone did. A volunteered answer shows what they say they want. The two often disagree: a shopper may tell a retailer they prefer sustainable brands and still buy the cheapest option.
Neither is wrong. Stated intent is better for understanding motivations and planning stock; observed behaviour is better for predicting the next purchase. Good analysis usually combines them.
Where stated answers are strong and weak
- Accurate on the facts people know best: shoe size, dietary needs, the month they plan to move house.
- Weak on anything socially loaded, where people answer the way they think they should.
- Goes stale. A stated budget or travel plan from last spring may be meaningless now.
- Small. Only a fraction of visitors complete a quiz, and they are rarely a random sample.
A worked example in a brokered deal
This is a made-up scenario to show the reasoning. Picture a recipe app whose sign-up flow asks users about allergies, diets they follow, household size and how often they cook. After several years it holds answers from a large user base and a food manufacturer asks whether it could license them to plan new product lines.
Why user-level answers can't move
A broker looking at this would start with the promise made on the sign-up screen. Users answered so the app would show them suitable recipes. Nothing suggested the answers would leave the company.
Allergy and diet details can also edge towards health information, which attracts stricter treatment in many privacy laws. Handing over user-level answers would break the expectation that made people answer honestly in the first place.
What can work is a report rather than a file. The app produces aggregate tables, for example the share of households in each size band that say they avoid gluten, with small groups suppressed so no individual can be singled out.
The food manufacturer licenses those statistics. Nobody's personal answers are transferred, and the app's privacy notice is checked to confirm that even aggregate sharing is covered.
Zero-party data beside related terms
| Term | How it is captured | Who holds it | Typical use when money changes hands |
|---|---|---|---|
| Zero-party data | The person answers a question on purpose | The business that asked | Aggregated into insight reports; individual answers seldom move |
| First-party data | Recorded as people use the business's own channels | That same business | The usual raw material for a licence |
| Consumer data | Any route, about individuals as shoppers or residents | Retailers, apps, brokers, public bodies | Marketing audiences, risk checks, research |
| Intent data | Inferred from research behaviour across many sites | Publisher networks and data providers | Sold as signals that an account is in market |
Why it matters to a broker
Sellers sometimes assume volunteered answers are their most valuable asset because they are clean and specific. For a brokered sale they are often the hardest asset to move.
Checks before treating answers as inventory
Before treating them as inventory, check what people were told at the moment they answered, whether any question touched sensitive categories, and whether the insight can be delivered as aggregates. A clean room, where the buyer queries data without receiving it, is another route some companies use.
Limits worth stating plainly
Most people searching this phrase are marketers building preference centres, not people arranging data deals. If that is you, the main lesson is to ask only what you will use and to say clearly how answers will be used.
For anyone brokering, the lesson is the reverse side of the same coin: the narrower the promise at collection, the narrower the deal.
More about zero-party data
Where the term comes from
The phrase was coined by the research firm Forrester, which framed it as data a customer intentionally and proactively shares with a brand. Some marketing teams call the same thing explicit data. The point of the extra category was to separate what people say about themselves from what a company deduces by watching clicks and purchases.
Typical sources are preference centres, onboarding questionnaires, style quizzes, wish lists, "tell us about your trip" forms and replies to a post-purchase survey. The person knows they are answering a question. That awareness is what gives the information its value, and it is also what limits where the information can go next.
Sources
2 sources · checked Nov 7, 2026
- Salesforce: What is zero-party data?The term's origin at Forrester, its definition and the explicit data alias · Checked
- European Commission: What is personal data?That individual answers are personal data and only irreversibly anonymised data falls outside the GDPR · Checked
Zero-party data FAQ
What is an example of zero-party data?
A shopper telling a clothing site their size and favourite colours in a style quiz, or a traveller ticking which destinations interest them in an airline's preference centre.
Is zero-party data the same as first-party data?
It is usually treated as a slice of it. Both are gathered by the business itself; the zero-party label just marks the parts people volunteered rather than the parts the business observed.
Who coined the term zero-party data?
Forrester Research introduced it, describing information a customer intentionally and proactively shares with a brand.
Does zero-party data need consent?
Answering is a choice, but that does not cover every later use. What people were told about how their answers would be used still governs what the business may do with them.
Related
- First-party data
First-party data is what a business gathers itself, from its own customers, systems and operations, rather than buying it in.
- Consumer data
Consumer data covers information about individual people in their private lives: who they are, where they live, what they buy and do.
- Second-party data
Second-party data is another company's own first-hand data that you get directly from them, through a partnership or licence.
- Data clean room
A data clean room lets companies run agreed analyses across their combined data while each keeps its raw records out of the other's hands.
- California data broker registry and the Delete Act
The California data broker registry, run by the state privacy agency, sets yearly registration, a deletion platform every broker must check, and daily fines.
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