The size of the advertising market is difficult to assess, and estimates by analysts vary to some degree. This is partly due to the fact that the final cost of advertising for any company includes creative and agency costs; local branding and marketing efforts; catalogs, brochures and other printed matter; the creation and maintenance of web sites and myriad other components, in addition to expenses for media. Numbers that are available for analysis and comparison are generally limited to actual spending on media, such as radio, TV, billboards and paid search or Internet advertising. Even these numbers are often educated guesses. Estimates of ad spending may include spending at both local and national media outlets, as well as spending on Internet media via paid search and online ads. Recently, spending on social media sites has been added to the mix.
Among the best growth areas in advertising are advertising on mobile devices, which is still in its infancy, and advertising online. Analysts at Gartner expect mobile advertising to reach $24.6 billion worldwide by 2016. ZenithOptimedia estimates that global digital advertising, including online search, will reach $101.5 billion in 2013.
Advertising is irrevocably linked to media, whether traditional media like the 15,302 broadcast radio stations in America (about $16.5 billion in annual revenues); 2,034 commercial broadcast TV stations plus myriad cable and satellite TV outlets (totaling about $66.4 billion in advertising revenues); the 1,382 daily newspapers