Agency Report 2007 : Things are Looking Up!

Advertising Age - U.S. Agency Revenue Jumps 8.8% to $28.2 Billion

Sea Change: Internet Drives Marketing- Services Gains; JWT Top U.S. Agency Brand; Dentsu Leads World Chart By Bradley Johnson
What's behind the change? No surprise: the internet. U.S. interactive-agency revenue rocketed 23.1%, driving the increase in marketing services. But digital is more than interactive shops; it's an integral part of marketing services from direct to promotion.
Link to charts, rankings and analyses in Agency Report 2007.