Eyal admits that, if used for harmful purposes, the Hook model is a “recipe for manipulation” and should leave the reader feeling “unsettled” (164). He argues that since product design can be very persuasive and change people’s behavior, designers have a responsibility to ensure that their products will help, or at least not harm, the user. Eyal claims that manipulation is a ubiquitous marketing strategy used by all kinds of companies, and that the technology industry in particular must adopt an “ethical code of conduct” (166).

His ethical code is based on his “Manipulation Matrix.” This requires designers to consider if they would use their own product, and whether their product will improve the user’s life. There are four possible answers to these questions. If the designer would use their own product and believes it will improve the user’s life, the designer is a “Facilitator.” This is the most ethical and helpful type of designer who “build[s] the change they want to see in the world” (171).

If the designer believes their product will help others, but would not use it themselves, they are a “Peddler.” Eyal claims that this group tends to struggle to understand their clientele, as they do not identify with the demographic using their services.