This IDC study forecasts expenditures on Internet advertising for all worldwide regions and the United States for 2009-2013. For the United States, it predicts the overall volume of spending on Internet advertising, breaks out spending by advertising format including mobile advertising, and also provides ad spend on social networking services, behavioral targeting. Top-line numbers for all major traditional media are also included.

"Advertisers will spend less on online advertising in 2009 because of the recession. But online ads will still do better than advertising overall or the economy at large, and they will continue to gain market share at the expense of old media," says Karsten Weide, program director, Digital Marketplace: New Media and Entertainment. "Video ads, mobile ads and behavioral targeting will grow strongest in the years to come."