This paper concerns theories around the ‘psychology of selling’ advanced in New York at the end of the 1920s by two figures with strong Viennese connections. Kiesler was an avant-garde polymath—an ‘International Constructivist’ De Stijl member who brought innovative theories of display to America with his arrival in 1926 to curate the International Theatre Exposition. Two years later he produced ground-breaking window displays for Saks Fifth Avenue department store, and also published a treatise on store decoration in which he outlined new possibilities using spatial arrangements and technical devices to stimulate sales. In doing so, Kiesler adapted avant-garde principles of affective transformation to a commercial agenda. In 1928, Bernays’s Propaganda heralded the nascent industry of Public Relations. As Sigmund Freud’s nephew, Bernays (an Austrian-American whose family arrived in the USA when he was an infant) had special insight into the psychological factors that underlay the purchasing habits of the masses, and in his book outlined techniques for their manipulation. If Bernays ultimately aimed to generate consumption, Kiesler’s theories attempted to balance practicality with the utopian idea of a harmonious social totality. In this paper, I explore these two contrasting versions of shaping the spending habits of Americans in relation to later Frankfurt School theories about the mass mind as an ideological battleground.