US online ad revenue hit US$21.2B in 2007

US online ad spending increased 26% in 2007 over 2006, as the Google-dominated search format not only remained the market's largest, but also increased its share of the overall pie.

Online ad spending in the US reached US$21.2 billion last year. Search advertising accounted for 41% of the spending, one percentage point more than in 2006, the Interactive Advertising Bureau reports. In 2007, spending in search advertising grew 30% over 2006, explaining the continued financial success of Google, which broadly dominates this format.

It also partly explains Microsoft's continued sense of urgency at trying to boost its underperforming internet ad business, which hasn't been able to achieve its financial and usage goals, specifically in search advertising, despite heavy investments in recent years. Microsoft cited its desire to compete better against Google as a key incentive in its attempt to acquire Yahoo, an effort that Microsoft has, at least for now, given up on.

Display advertising, which includes formats like banners, sponsorships and video, accounted for 34% of the spending, according to the IAB. This is a category in which, according to IDC, Yahoo leads and Google has a minor position. The third-largest format was classifieds, with 16%.

A majority of the spending -- 55% -- came from companies advertising products and services for consumers, such as retail, automotive, leisure and entertainment companies. Providers of financial services made up the second-largest category with 15% of the spending.

In 2007's third quarter, spending reached almost US$5.3 billion, and in the fourth quarter it almost hit $6 billion, according to the IAB.

The 10 largest online ad sellers racked up almost 70% of the spending, while the top 50 captured 89%.