What is popunder? Therese Johnsen August 22, 2017 09:28 Updated Follow A popunder is a advertisment that opens a new window/tab behind the page you are viewing at the same time. Related articles Problems with adding a profile on chaturbate? Introduction to DivaTraffic What is BoostMyCam? What is CamHead? Where is the traffic comming from? Comments 0 comments Article is closed for comments.