Editor’s note: Steven Millman is SVP global research and operations, advertising solutions, at data and insights platform Dynata. 

Zeroth-party data is a relatively new term in the market research industry which appears to have originated at Forrester in 2018 (account required to access) and describes a way to divide what has traditionally been referred to as first-party data into two groups based on the conditions under which the data were collected. 

The name “zero-party data” is inconsistent with the nomenclature. Given the use of ordinal terms for the other types (first, second, third), the only really appropriate name for this would be zeroth party data. Using the cardinal zero fails to align with the rest of the existing nomenclature and confounds one’s sense of mathematical consistency. I do math for a living, so I’ll be using “zeroth-party data.”

Before I dive further into zeroth-party data, let’s take a brief look at first-, second- and third-party data. 

First-party data refers to data that a brand or research firm collects directly, owns and has implicit or explicit rights to use. Implicit rights might include those that arise from a brand’s direct relationship with its customers, like sales or other CRM data, e-mail lists or website interactions. Explicit rights are those granted voluntarily by the source of the data such as survey data, voluntary meters or accepted cookies used by the publisher (as opposed to some third-party entity).

Second-party data is not collected directly by the user of the data but rather is obtained by them from the legitimate first-party owner. This can be as simple as buying the data from a first-party owner who has the rights to sell them or can be the combination of two first-party data sets where both owners have the rights to combine them. When obtaining second-party data, it’s in your interest to be very cautious and verify that the data owner...