Links associated with a billboard will always open in a new, separate page/window. There should be an option to open the link in the current page/window OR a new page/window. The reason for this is that if you have a link to an Absorb spot and the learner clicks on the billboard, they now have 2 windows open to Absorb. Before long they have multiple windows open to Absorb and they get confused about what course they are in and what they are doing.