Figures from a study conducted by researcher Efficient Frontier suggest that spending on Google accounts for three-fourths of the money spent on search marketing in the U.S.

Search Engine Land editor Matt McGee writes that the report offers an "overall positive outlook on search advertising," and that the search giant’s two biggest competitors – Yahoo and Bing – each dropped varying amounts of market share for paid clicks during the fourth quarter of 2009.

While the amount spent on search engine optimization (SEO) and other search marketing channels from the retail sector went up during studied time period, the report indicates that it failed to reach 2008 levels. Consumer search volume, by contrast, shot up fully 66 percent from Q4 2008 for the financial sector, and the Cash for Clunkers program contributed to a noticeable bump in automotive search during 2009.

Experts say that online marketing was hit more softly than many sectors of the economy during the recent economic downturn, and that it could be set for a boom as U.S. consumers begin to spend again.