Digital advertising for gambling and specifically marketing via social media have increased in recent years, and the impact on vulnerable consumers, including moderate-risk and problem gamblers, is unknown. Social media promotions often fall outside of advertising restrictions and codes of conduct and may have an inequitable effect on susceptible gamblers. This study aimed to investigate recall of exposure to, and reported impact on gamblers of, gambling promotions and marketing content on social media, with a focus on vulnerable users currently experiencing gambling problems. Gamblers who use social media (N = 964) completed an online survey assessing their exposure to and engagement with gambling operators on social media, their problem gambling severity, and the impact of social media promotions on their gambling. Gamblers at moderate risk and problem gamblers were significantly more likely to report having been exposed to social media gambling promotions and indicated actively engaging with gambling operators via these platforms. They were more likely to self-report that they had increased gambling as a result of these promotions, and over one third reported that the promotions had increased their problems. This research suggests that gamblers at moderate risk or those experiencing gambling problems are more likely to be impacted by social media promotions, and these may play a role in exacerbating disordered gambling. Future research should verify these self-reported results with behavioral data. However, the potential influence of advertisements via these new platforms should be considered by clinicians and policymakers, given their potential role in the formation of this behavioral addiction.