I’ve been looking around for a while trying to find data that compares advertising spending on the internet with spending in other channels. And did I ever find it!
U.S. advertising expenditure, for various media and type categories across the years 1919 to 2007, is now available in a dataset convenient for extensive analysis. These data quantify the rise of advertising on radio, on television, in telephone directories (yellowbook), and on the Internet. They also quantify less widely discussed media for advertising, such as direct mail, billboards and outdoor advertising, and advertising in business papers (trade press).