While the social media app Snapchat has increasingly attracted the attention of millennials around the world, there is limited empirical research dealing with Snapchat marketing. For businesses, it is imperative to know how effective Snap Ads are at reaching millennials. Based on the uses and gratifications theory (UGT), this study aims to fill this research gap by identifying millennials’ motives for using Snapchat and analyzing how they affect their attitudes toward Snap Ads and the subsequent behavioral intentions. Some 265 Saudi, Snapchat-using students aged between 18 and 35 completed an online survey. Our data analysis employed exploratory and confirmatory factor analyses, as well as structural equation modeling. The results indicate that respondents seek four forms of gratification from using Snapchat, namely information seeking, self-expression, entertainment, and social interaction. Of these, only information seeking and entertainment were found to have significant positive influences on attitudes toward Snap Ads, intentions to share then, and purchasing intentions. This research contributes to the theory by proving that the UGT is suitable for gaining knowledge about consumer behavior on social media in general, as well as by proposing a framework for studying the persuasive effectiveness of Snap Ads in particular. From a practical perspective, this study offers guidelines on how customized Snap Ads can be conceived for millennials, so they will not irritate them.