For the study, which was sponsored by Google, comScore examined searches in November and December conducted by 100,000 consumers, and then surveyed a sample of 800 individuals.
James Lamberti, comScore vice president of marketing solutions, said the results show that Web-only metrics--such as click-through rates and online conversions--don't tell the whole story of how a search campaign is performing.
"The ROI being realized here is significantly higher than the analytics packages can pick up," said James Lamberti, comScore vice president of marketing solutions. "The vast majority of marketers are not linking the fact that search is actually pushing people into the storefront as it is."
The split between online and offline conversions varied between the categories, but in each, the majority of conversions were made offline in physical stores, the study found. comScore looked at searches and purchases in a variety of categories, including consumer electronics, movies/videos/music, clothing, jewelry, and video games, among others. The highest rate of offline buyers came in the video games and consoles category; 17 percent of searchers in that category converted, but fewer than one in 10--7 percent--did so online. In apparel and accessories, by contrast, 43 percent of searchers converted, but more than one in three--35 percent--made purchases on the Web.
Lamberti added that many marketers have yet to realize that the majority of their return on search investment come from offline buyers. "The critical thing is that it changes the ROI equation. There's still a tremendous amount of headroom in the ROI, given that so much of the conversion is related to the store itself," he said. "If you're lacking a physical store, given the consumer behavior we witnessed here, you're going to be at somewhat of a disadvantage on your return on investment."
David Berkowitz, search marketing firm 360i's director of strategic planning, took another view. He contended that many marketers were indeed aware of the ROI gleaned from offline conversions, but said the major challenge was figuring out how to measure the offline conversions stemming from search. "There's still more room in terms of improving the measurement of offline channels for interactive campaigns," he said. "That remains a significant challenge for marketers."