What is Data marketplace?

How a data marketplace works

The core job is matchmaking. A peer-reviewed analysis describes data marketplaces as starting data transactions by matching data holders with prospective data users. The OECD describes them as online platforms that host data from various publishers and offer it, possibly enriched, to interested parties.

The broader “data market” is, in the OECD’s words, the place where digital data is exchanged as products and services resulting from the (re-)processing of raw data. A marketplace is one venue within that market.

How regulators use the term

The EU’s Data Governance Act (DGA) attaches its obligations to data intermediation services, not to the label “marketplace”. It defines these as services that aim to set up commercial relationships for data sharing between an undetermined number of data holders or data subjects on one side and data users on the other, through technical, legal or other means. According to a law-firm overview, the DGA names data marketplaces where companies make data accessible to other companies as an example, and the Dutch government says matchmaking services such as a data marketplace are covered. The DGA has applied since 24 September 2023.

Providers in scope must stay neutral about the data exchanged, notify the competent authorities in advance, and offer the service through a separate legal entity. One academic reading of Article 12 adds that intermediaries should not use the data for other purposes, though supporting functions such as anonymisation are allowed. This is general information; whether a given service is in scope is a question for counsel.

Marketplace vs. data broker

A data broker resells personal information about consumers; a data marketplace matches data holders with data users, and can be limited to business data that companies choose to list. The US Federal Trade Commission describes data brokers as companies that collect personal information about consumers from a variety of sources and resell it to other companies. California’s Delete Act, per a law-firm summary, covers businesses that sell consumers’ personal information when they have no direct relationship with those consumers.

Why it matters if you sell data

What leaves your hands? In guidance published in March 2025, the UK ICO says pseudonymous information is still personal data: pseudonymisation reduces the links between people and their data, while anonymisation prevents a link. It also notes that datasets are often called “anonymised” when they still contain pseudonymised personal data. Ask exactly what is removed and what the limits are.

Do you have the right to sell it? FTC staff have warned that adopting more permissive practices, such as starting to share consumers’ data with third parties or use it for AI training, and disclosing this only through a hidden, retroactive change to terms may be unfair or deceptive. This is general information; check your customer contracts, privacy policy and employee communications policies with counsel.

Who decides? Look for seller approval of each buyer, price and term, and a way to unlist.

On SellMyData, for example, names, contact details and identifiers are replaced with consistent placeholders, every dataset goes through a rights check before listing, buyers see only a redacted sample before purchase with scope, format, exclusivity and term agreed per dataset, and nothing is licensed without the seller’s sign-off; data can be unlisted and deleted at any time.