Over its first decade Instagram became central to Facebook’s dominance of audience and advertising markets. In this article, we critically examine how marketing and advertising trade press documented the development of advertising and retail on the platform. Instagram’s platformization involved formalizing relationships among users, influencers, creators, advertisers, retailers, and analytics services. The development of advertising and retail on the platform was characterized by open-ended third-party experimentation and innovation, which was gradually incorporated into, and controlled by, the platform. Advertisers and marketers increasingly approach the platform not just as an advertising service, but an end-to-end advertising, analytics and retail infrastructure. While much attention has been given to the promotional and influencer culture of Instagram, advertisers and marketers saw it as an opportunity to integrate advertising with retail. We argue that Instagram has platformized practices of looking and buying historically associated with department stores, malls, home shopping, and catalogs.