Home/Ad Tech/Data & Taxonomy/Data Marketplaces
Where it sits in the stack
Data & taxonomy layer
A cross-cutting capability used across the buy and sell sides, rather than a single point in the auction chain.
Data & Taxonomy · DMKT

Data Marketplaces

A data marketplace is a platform where audience data segments are bought and sold, letting advertisers license third-party data to enrich targeting.

Updated 2025-07-06 Author Luc Dumont Reading time ~4 min

Key takeaways

  • Data marketplaces let advertisers license third-party audience segments.
  • They historically supplied the segments that powered DMPs.
  • Segment quality, provenance, and accuracy vary widely.
  • Cookie loss and curation have reshaped how audience data is sourced.

Licensing audience segments

Data marketplaces aggregate segments from many providers "” 'auto intenders,' 'new parents' "” and let buyers license them for targeting inside DSPs and DMPs. They created scale but also opacity: buyers often couldn't verify how a segment was built or how accurate it was.

From marketplaces to curation

As third-party cookies decline and buyers demand provenance, the industry is shifting from open third-party marketplaces toward curation and first/second-party sourcing "” packaging vetted, often deterministic audiences with clearer origins, frequently assembled on the sell side or in clean rooms.

At a glance
What it isMarketplace for audience segments
Data typeLargely third-party
WeaknessOpaque provenance and accuracy
TrendToward curation and first/second-party

Frequently asked questions

What is a data marketplace?

A platform where advertisers license third-party audience segments "” like in-market or interest groups "” to enrich their targeting.

Why is third-party data from marketplaces declining?

Cookie deprecation reduced its reliability, and buyers increasingly demand transparent provenance, pushing sourcing toward curated first- and second-party data and clean-room matches.