This study sought to identify effective advertising strategies for application service providers regarding mobile applications that many brands have recently been utilizing as a marketing tool. In particular, the study focused on examining how consumers' familiarity with advertised brands (number of associations) and the relevance between content and advertisements affect application service providers that use applications as advertising media. Six hypotheses established using transfer effect theory, advertising intrusiveness theory, and contextual advertising theory were analyzed through two experiments. The analysis results revealed the following. First, placing advertisements for brands with a high number of associations in mobile applications actually decreased consumers' loyalty toward and usage intention of the application providers compared to placing advertisements for brands with a low number of associations. Second, when advertisements were relevant to the content, consumers had more favorable attitudes toward the application than when they were not, but this did not significantly affect loyalty and usage intention. However, when advertisements relevant to the content were placed within mobile applications with a low number of associations and low familiarity, consumers showed higher loyalty and usage intention toward the application. This study will contribute theoretically to the field of mobile advertising research and will provide useful practical implications for application service providers that place mobile advertisements.