This document discusses different types of media used for advertising, dividing them into above-the-line media (such as TV, radio, outdoor advertising) and below-the-line media (such as direct mail, sales promotions). It then categorizes media types in more detail, including print media (newspapers, magazines), broadcast media (radio, TV), outdoor media (billboards, posters), transit advertising (on buses or trains), and other media (specialty items, direct marketing, internet). The document notes that while print and electronic media were the first revolutions, digital media such as the internet now allows for more interactivity and customization in advertising.