Zero-Party Data.

Zero-party data is information that a customer deliberately and proactively shares with a brand—not observed or inferred, but explicitly given. Examples include: preference centre selections ('I'm interested in X topics'), quiz responses ('I have oily skin and want anti-aging products'), purchase intent signals ('I'm planning to buy a CRM this quarter'), and feedback forms. The term was popularised by Forrester Research.

Zero-Party vs. First-Party Data

First-party data is observed (what users do on your site); zero-party data is declared (what users explicitly tell you). Zero-party data is arguably more valuable because it's direct expression of preference without inference error, tends to be highly accurate, and because users gave it willingly, they expect relevant personalisation in return. The exchange is transparent: 'share your preferences with us, and we'll provide a more relevant experience'.

Collecting Zero-Party Data

Effective zero-party data collection uses value exchange: quizzes that provide personalised product recommendations in exchange for preference data; preference centres where subscribers choose content types and frequency; onboarding questionnaires that improve product experience; and surveys with immediate personalised results. The key is providing genuine value in return—users who complete a quiz for a personalised outcome willingly share detailed preference data that would be impossible to infer from behaviour alone.