Interactive advertising is responsible for $300 billion of economic activity in the U.S., according to the below study released by the IAB. The advertising-supported Internet represents 2.1% of the total U.S. gross domestic product (GDP). It directly employs more than 1.2 million Americans with above-average wages in jobs that did not exist two decades ago, and another 1.9 million people work to support those with directly Internet-related jobs. A total of 3.1 million Americans are employed thanks to the interactive ecosystem. These are the key findings of the first-ever research to analyze the economic importance, as well as the social benefits, of the Internet.
The study, commissioned by the IAB was produced by Harvard Business School professors John Deighton and John Quelch, along with Cambridge, MA-based Hamilton Consultants. The study was designed to provide an impartial and comprehensive review of the entire Internet economy and answer questions about its size, what comprises it, and the economic and social benefits Americans derive from it.
http://www.iab.net/media/file/Economic-Value-Report.pdf