Alter is an author and a professor at New York University Stern School of Business. His specialties include marketing and psychology. Alter narrates Irresistible in the first person, drawing from a wide range of case studies, academic articles, psychological experiments, historical research, and interviews to support his assertions regarding the rise of behavioral addictions in the age of the internet and smartphones. Alter occasionally uses personal anecdotes, noting his own experiences with behavioral addictions and online games. At one point, Alter reflects on his newborn son and imagines the world of screens his son will inherit. For the most part, however, Alter remains absent from the narrative. Instead, he frames Irresistible as a series of claims and arguments that he supports with evidence drawn from beyond his personal experience. 

One figure Alter refers to several times throughout the book is Vaisberg, a young man who battled an addiction to the online game World of Warcraft. Vaisberg first appears in Chapter 2, “The Addict in All of Us,” to serve as a reminder that almost anyone can fall victim to addiction. Vaisberg was a talented student before succumbing to long World of Warcraft binges that ultimately drove him to the reSTART treatment center near Seattle, Washington.