The purpose of this lesson is to study the concept of placing advertising in what is known as fixed positions vs. ROS or run of station/site in media and the very important concept of Posting a media placement. This lesson will not only address differences in pricing but will also serve to understand the concept of media delivery on audience projections. The business of media keeps changing with more programming choices to choose from and more platforms of delivery, but some principles of the business remain true and need to be understood to become better marketing, media, and advertising professionals.