Advertisements (ads) in social networking sites (SNSAs) have been considered by many researchers as a crucial area of research. However, the scope of the existing studies on consumers’ assessments of SNSAs has been very limited. Most of the existing studies on assessing SNSAs have focused on Ducoffe’s (1996) model with its three variables, and they have ignored other related variables like the credibility value and interactivity value of the advertisement, which are more logically related to SNSAs than the traditional ads. Moreover, most of these studies have been skewed towards younger users and have ignored the social networking site (SNS) users from other age categories. Finally, previous studies about the assessment of SNSAs have depended on data collected from users of popular SNSs and ignored active users from the brand communities (fans of brands on SNSs). In this thesis, the present author has emphasized these three points as the major gaps in the literature about assessing SNSAs. Moreover, to deepen our understanding of how SNS users assess SNSAs this study presents the research findings of three published papers with three different purposes and with different levels of analysis. The first article aimed to extend Ducoffe’s (1996) model – which was used in the previous literature in assessing SNSAs – by considering the ads’ credibility and interactivity values in addition to Ducoffe’s (1996) three variables of information value, entertainment value, and irritation value. A multiple regression analysis was used to test the modified model, and based on the regression analysis of testing the five predictors, the model without the irritation value had the best coefficient of determination (R2). Moreover, coefficient analysis to test the given hypothesis and to determine the coefficients of the predictors was used. According to this survey study, the four primary variables that predicted the consumers’ assessment of the SNSAs were the information value, entertainment value, credibility value, and interactivity value. As perceived by the SNS users, the interactivity value was the strongest among the four predictors. Based on the unexpected result ofthe irritation value of the first paper, the second paper focused on testing the extended model of the assessments of SNSAs as perceived by a different research population, in this case, brand communities’ consumers (BCCs). Based on the regression analysis of testing the five predictors, the model with the five predictors had the best coefficient of determination (R2). The coefficient analysis was used to test the given hypothesis, to determine the coefficients of the five predictors, and to form a construct equation for assessing the SNSAs. Based on this survey study, the four variables with significant positive effects on the consumers’ assessment of SNSAs were informativeness, entertainment value, credibility value, and interactivity value, while the fifth dimension (irritation value) had a significant negative coefficient on the consumers’ assessment of SNSAs. Moreover, that study provided a deeper understanding of how the BCCs assess SNSAs, and it contributed to identifying the main characteristics ofthe BCCs on an SNS. The third paper focused on exploring the effect of national culture on the consumers’ assessment of SNSAs. The cultural features of the respondents in that study gave additional evidence about how a nation’s cultural characteristics can influence the consumers’ assessment of SNSAs. This study helped to identify how SNS users from Egypt, the Netherlands, and the United Kingdom assess SNSAs. In this study, one-way analysis of variance with post hoc tests was used to compare the assessments of the three nations. Based on the empirical findings of this survey study, the three groups had significant difference F-ratios for their perception of four of the five variables for assessing SNSAs. Their perceptions of the entertainment value did not significantly differ between the three groups while the interactivity value had the strongest F-ratio. The overall purpose of this study was to deepen our understanding of how SNS users are assessing SNSAs in different settings by considering SNS users, BCCs, and others from various nations. All of the studies presented here have focused on variables for assessing the ads that have been used by other researchers in different research contexts.