Communication researchers examining how audiences are commoditised in the audience marketplace by commercial media providers and advertisers have been using audience economic models that were applied to commercial television, radio and print audiences. New digital technologies are transforming the way audiences are commoditised and previous models of the audience marketplace are not applicable to the new audience marketplace. This paper examines how audience economy and audience marketplace theories evolved and describes how programmatic advertising—the automated trading of the audience commodity—differs from previous audience theories requiring a need to re-examine these theories. New digital technology is being used to not only find audiences online but also uses data to create profiles of individuals audience members. The datafied audience plays a central role in the programmatic trading of the evolving audience commodity and the new audience marketplace that has emerged.