third-party cookies

The difference between zero-, first-, second-, and third-party data

Data is incredibly valuable to marketers, agencies, and publishers, since it is used to power advertising models and generate revenue. And the amount of data we produce is accelerating. The global volume of data reached 64.2 zettabytes in 2020, and this is predicted to double by 2025.

However, privacy regulations, such as GDPR and CCPA, have made data an increasingly difficult resource to tap. In response, the online advertising industry has developed different classifications of data to help with the handling process. So, what do the terms zero-, first-, second-, and third-party data mean?

Four-party state

The ad tech industry uses four different classifications of data, depending on the degree of separation from the source of information.

Zero-party data

This relatively new term describes data which is willingly shared directly with the recipient, e.g., a customer who bought a sneaker submitting a survey to the brand. Arguably, this is a type of first-party data, the distinction being that it’s intentionally handed over rather than automatically collected.

Zero-party data also refers to edge computing ad solutions, where data is processed on-device rather than transmitted elsewhere online. This protects user privacy by minimising the data collected, while still allowing behavioural targeting and personalised ads, thereby circumventing legal restrictions on the amount of data allowed to be sent to the bidstream.

First-party data

Data which is gathered directly, for instance from customers, visitors, or social media followers. This includes information from email interactions and behaviours on a website or app. First-party data differs from second- or third-party data in that there is no intermediary between the supplier and the recipient of the information.

First-party data includes first-party cookies and advertising IDs which identify individual visitors, such as GAID, IDFA, and UID. Identity solutions use these IDs to track user behaviour while they interact with a website or app, in order to serve behavioural and contextual ads. However, targeted ads relying on first-party data alone can be sub-optimal, since their reach is limited to information from a single platform or site.

Second-party data

This refers to data collected from a partner who has in turn gathered it directly from visitors or customers. Although the data is supplied by another agent, the distinction made from its close third-party relative is that second-party data is sourced from a trusted partner, with whom there is a direct agreement on how the information is to be exchanged and used. The transaction takes place in a closed environment, such as a data cooperative, or a data “clean room” which provides the utmost security and privacy. Second-party data is usually used to periodically enrich first-party data to gain insights.

As with zero-party, there is some contention over the term ‘second-party data’, and the disagreement makes its definition a little woolly. In fact, when the Winterberry Group asked industry experts for the definition, responses ranged from “someone else’s first-party data”, to “there is no such thing”. After pinning down some specifics, the researchers proposed that any commercialisation or licensing of second-party data transforms its state into third-party. But this is by no means a hard-and-fast rule.

Third-party data

This pertains to any data received indirectly, via an intermediary agent who is not the original source. In ad tech, this data is usually gathered, aggregated, and packaged to be sold to companies to build advertising strategies.

Third-party data has historically been the most sought after in personalised advertising, allowing one-to-one retargeting of an online user. This can be achieved via cross-tracking cookies, where a user’s profile follows them online and is appended with data from each site they visit. Knowing so much about a user enables hyper-targeted ads to be served to them. However, third-party data now sees the most legal scrutiny due to the privacy implications of tracking users so closely across different sites, hence the phasing-out of third-party cookies.

So… where’s the party?

If all this has left you confused about the classification of data, you’re not alone. The rise of zero-party data, and the explosion of second-party data, are a result of initiatives by the industry to avoid falling foul of privacy regulations while retaining access to sources of data which make advertising models effective. In the age of big data, just make sure you know the legal requirements when handling it, so you can avoid having your party busted.

Image courtesy of Joshua Sortino