Since Zajonc hypothesized the basic idea of mere exposure - more exposure to a stimulus tend to preference for it, - more phenomena of mere exposure are suggested by subsequent studies as well as his further experiments. Supportive studies have provided experimental and statistical evidences for it, showing that subjects tend to have more favorable attitude toward familiar objects because of their mere exposure effect. Zajonc also expanded his first hypothesis into non-conscious process without cognition and studies the relationship of affect and cognition to find the result that the mere exposure effect did not always depend on the recognition of stimulus. Further, regarding feeling of human beings, other supportive research show strong evidences that emotion and thinking have different controlling structures in the human brain. Those are crucial founding to imply people sometimes feel before they think. In this point, the mere exposure effect is linked with the subliminal advertising effect. As Zajonc (2001) states, "exposure effects are more pronounced when obtained under subliminal conditions than when subjects are aware of the repeated exposures(Zajonc, 2001, p.225). Further, "vast literature on the mere-repeated-exposure effect shows it to be a robust phenomenon that can not be explained by an appeal to recognition memory or perceptual fluency"(Zajonc, 2001, p.225)

Those empirical evidence of the mere exposure effect in both psychology and advertising suggests also that mere exposure to an advertisement leads to increased liking and affects subsequent judgment. As shown in this paper, advertising has mainly explored whether multiple exposure to a persuasive message increases or decreases persuasion effects. Those approaches are crucial to study consumer behavior as well as advertising effect. Recently, they are used to understand attitudes toward computer-mediated advertising and even other marketing promotions beyond advertising as the scope and type of advertising become broaden and diversified.

However, there are several limitations of the mere exposure theory, which are based on the primary limitation of attitude theory as well as the limitation of its own theoretical discussion. It also remains to be demonstrated how permanent are preferences induced by mere repeated exposures. The one things we should remember are the debate on the mere exposure effect is not stopped yet and this debate would be helpful to make the theory much richer and stronger. Most of all, despite several limitations of mere exposure effects, it is now called "the mere-repeated-exposure paradigm"( Zajonc, 2001, p.225) to explain how familiarity breeds preference in many areas beyond psychology.

In the mere-exposure theory, its basic idea is effective but surprisingly simple: all that is needed to produce an attitude of greater liking for an object is merely repeated exposure to the object. Bargh (2001) points out that it is the landmark of Zajonc's mere exposure theory to discover this basic and simple mechanism in the chaos of apparent complexity such as social psychology. Probably from the long discussion on mere exposure effect what we should learn is when confronted by confusion, seek out the profound simplicities.