What is run of site (ROS) advertising?

Run of site advertising means that your banner ads will be displayed throughout an individual website, across all its banner ad real estate. ROS advertising is often less expensive than advertising in a specific area on a website. On portal sites, such as Yahoo.com or MSN.com, ROS advertising can be a dramatic savings over targeted marketing. While most products or services will benefit from targeted marketing, products or services with broad appeal can have very successful online advertising campaigns using ROS advertising.