The IAB released its full-year 2006 Internet Advertising Revenue Report (here, PDF file) today. U.S. Internet ad spending was worth a total of $16.9 billion, with search accounting for 40 percent or around $6.8 billion, “up 31 percent from the $5.1 billion reported in 2005.” The category distribution of online ad spending was basically the same in 2006 as it was in 2005:
According to the report:
Search Continues to Lead, Followed by Display, Classifieds and Referrals—Search revenue accounted for 40 percent of 2006 full year revenues, slightly lower than the 41 percent for the full year 2005. Display advertising, Classifieds, and Referrals accounted for 32 percent, 18 percent, and 8 percent of 2006 full year revenues respectively.
The IAB defines “search” to include “paid listings,” “contextual search,” “paid inclusion” and “site optimization.”