Outdoor advertising usually comes in two forms: billboards and transit posters. Like yellow page ads, outdoor advertising is usually used to support advertisements placed in other media. One of the greatest strengths of outdoor advertising is as a directional marker to point customers toward your business. Since the prospective consumer often has only fleeting exposure to billboards and transit posters, the advertising copy written for these media needs to be brief with the ability to communicate ideas at a glance. To do this well one must use graphics and headings efficiently and artfully.