American online ad spend was 5% lower in the first half of 2009 than in the first half of 2008

"U.S. Internet advertising revenues [in the first half of 2009] were at $10.9 billion in that period, a 5.3% decline from the same period in 2008.
Search and display-related advertising continue to represent the largest percentages of overall interactive advertising spend. Search revenues amounted to more than $5.1 billion for the first six months of 2009, up slightly from that same period in 2008. Display-related advertising—which includes display ads, rich media, digital video and sponsorship—totaled nearly $3.8 billion in the first six months of 2009, showing a relatively modest 1.1% decline from the same period in 2008. Digital video continues to experience robust growth with a 38% increase from the first half of 2008."
Source: Press release reporting data from the Interactive Advertising Bureau (IAB) and PricewaterhouseCoopers LLP (PwC), 5th October 2009