The research investigates the mediating role of the consumer imagination in persuasion, depending upon level of involvement, nature of the purchase task, and ad information. The consumer imagination is conceptualized as combining triggered information from memory with incoming ad information to simulate a yet‐to‐be‐experienced event. The research reveals how obstacles to information flowing from memory or information from incoming peripheral ad claims suppress the enhancing effects of the consumer imagination. Across three studies, the findings indicate that few incoming peripheral ad claims are an obstacle to the consumer imagination in a utilitarian context, regardless of involvement, because preferred peripheral claims are reduced. Low involvement is an obstacle to the consumer imagination in a hedonic context, because it reduces the need to rely on triggered memories. However, this effect is reversed with more peripheral ad claims, because increased claims help to build up the imagination when reliance on triggered memories is reduced. Theoretical discussion is provided about how the imagination expands the elaboration of ad details by retrieving relevant experiences from memory to create mental rehearsals. Copyright © 2016 John Wiley & Sons, Ltd.