The results of the study also show that 25 percent of searchers purchased items directly related to their queries, and 37 percent completed their purchases online.

The study, which looked at the role of search in consumer buying and was sponsored by Google Inc., examined the impact of Web searches (excluding comparison-shopping sites) on consumers' holiday-related purchases -- both online and off-line -- in 11 product categories during November and December 2005. The study reflects the search behavior of 83 million Americans who conducted more than 552 million searches in the categories analyzed using one or more of 24 leading search engines, comScore said in a statement.

"The study confirms the important role of search in influencing consumers' purchase behavior, both online and off-line," James Lamberti, vice president of comScore Search Marketing Solutions, said in the statement. "Importantly, it's clear from this study that the influence of search on off-line buying can often be responsible for the major portion of the overall financial return from investments in search marketing."

According to the study, 43 percent of consumers who searched online for apparel and accessories actually made a purchase, with 65 percent of those shoppers buying at brick-and-mortar stores and the rest buying online. In comparison, while just 17 percent of consumers who searched for video games and consoles actually followed their search with a purchase, 93 percent of those who bought did so off-line, according to comScore.

ComScore also analyzed the time lag between consumers' initial searches and their later purchases during November and December. Like other comScore studies, this one found that 56 percent of consumers' online holiday buying actually happened in subsequent Internet sessions.