Glossary/Audience data/Second-party data
What is second-party data in advertising?
What second-party data is, how it compares to first- and third-party data, and how publishers use data partnerships.
Written by Samhub with the help of AI·Updated 13 Oct 2026·3 min readSecond-party data is another company’s first-party data, shared directly with you under an agreement, for example between a publisher and a retailer.
First, second and third-party data
| Type | Source | Example |
|---|---|---|
| First-party | Your own readers | Reading behavior on your site |
| Second-party | A known partner | A retailer’s customer segments |
| Third-party | Data sellers | Bought interest segments |
Common partnerships
Retail and media
Reach a retailer’s customers on your site.
Publisher alliances
Combine audiences for scale.
Brands
Match an advertiser’s customers for targeting or measurement.
16 pages for publishers, with a checklist for data, programmatic and direct sales.
Share safely
Use a data processing agreement, share pseudonymized data or work in a clean room, and make sure readers were told how their data may be used.
Addressability at Stampen Media after moving its reader data into one layer with Samhub.
Frequently asked questions
It is usually more accurate and transparent, since you know the source.
You need a legal basis for sharing, and clear information to readers.
Through direct transfers, clean rooms or shared identifiers.
They can offer audiences to partners, within GDPR limits.
Related terms
Data you collect directly from your own readers.
Data bought from providers who collected it elsewhere.
Data readers share with you on purpose.
Lets two parties match data without sharing it.
One EU-based platform to collect, unify and enrich your first-party data, installed with one script.
- A walkthrough with your own data
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- 30 minutes, no commitment
Turn your audience data into more revenue
Get the Media Monetization Playbook: how media houses turn first-party data into higher CPMs, data deals and direct sales. With checklists for every step.
