Advertising is a ubiquitous and substantial influence in consumerism, prompting psychological decision-making processes and behavioral consumerism. Selective marketing, advertising, and merchandising can only be successful when the processes within populations are identified and modified to fit the consumer. This paper examines psychological concepts surrounding the complex variables of decision-making. It will discuss relevant literature and empirical evidence that are imperative to further studies of behavioral consumerism. Such concepts that will be examined include: the elaboration likelihood model, regulatory focus theory, paradox of choice, as well as consumer variables such as influences of personality and maximizers versus satisficers. It then addresses these concepts through the lens of advertising and merchandising, and explores effective applications for behavioral persuasion and the implications for retailers.