A key benefit of web-based technology is the enhanced computational ability to tailor and personalize content using explicit online user profiles. While some degree of customization has long been regarded as positive, too much personalization to the point of perceived privacy intrusion can be detrimental. This study uses multivariate testing of an advertisement campaign on the online social network Facebook to investigate the extent to which digital advertising, personalized to specific age and gender group demographics (age and gender congruent) influences user engagement and increases click-through rates. The study achieved a total of 659,522 impressions (i.e., number of users who were exposed to the personalized advertisements and had the opportunity to engage). Moreover, a total of 1,733 unique clicks were recorded. Using N-1 χ2 testing, this study found that a combined age and gender congruency yielded statistically significantly greater click-through ratios in comparison to noncongruent (nonpersonalized) online advertisements (p < 0.05). As an example, the click-through rates by younger male users increased by over threefold when a young male model appeared in the imagery. The implication is that online content that is personalized to the user's age and gender demographic increases active user engagement.