Research on international migrants has seen a sharp increase during the last decades, yet sampling them remains a major challenge, especially in a cross-national setting and on a global scale. While various sampling methods are established in the field, most of them cannot easily be implemented globally due to their dependence on specific administrative or infrastructure elements or simply their costs. Since Social Networking Sites (SNS) operate on a global scale, they provide a sampling frame that can be utilized for the targeted recruitment of migrants worldwide. Increasingly used for research purposes and among the largest and most popular SNSs are Facebook and Instagram. In our project GEOOS (German Emigrants Overseas Online Survey), we utilize paid advertisements on these networks to target German emigrants, particularly Germans living outside of Europe. Our research aims to ascertain whether such ads could be used to recruit a nonprobability (migrant) sample on a global scale. More specifically, we are interested in the success of this approach concerning three performance indicators: Cost efficiency, coverage, and sample size. Our advertisement campaign ran for 18 days and resulted in total costs of about 2,223 Euro. This investment led a total of 3,895 individuals to complete the survey; of those, 98 percent belonged to the target population, meaning they were (a) either born in Germany or held German citizenship and (b) did not live in Germany. GEOOS participants lived in a total of 148 countries and territories around the globe. Similar to findings reported in previous studies on this target population, the largest sub-groups resided in predominantly Anglo-phone countries; however, taken together, participants in these countries only constitute 38 percent of our overall sample, with nearly a quarter of GEOOS participants (n = 867) living in Middle and South America, 862 residing in Asian countries, and 476 in Africa. Furthermore, a considerable share of our sample is constituted by individuals who would either not have been included in a sampling frame based on German population registers or who would have been unlikely to be reached through this method due to incomplete or outdated information.