Definition & Explanation

Third-party data is data purchased from external providers rather than collected directly from users. It is aggregated by data brokers who have no direct relationship with the data subjects, often gathered via third-party cookies and other tracking methods, then categorized by demographics, interests, and behaviors. While not as accurate as first-party or second-party data, third-party data allows advertisers to reach audiences at scale and gain insights into potential customers they would not otherwise know about.