Nearly half of consumers use a combination of search and social media to fuel their purchasing decisions, says a new study.

Search engines such as Google and Bing were the first stop for 58 percent of respondents, while 24 percent visited company sites and just 18 percent started with social media, says the survey, a joint project of comScore and search marketing specialist Group M Search.

Of those who went to search engines first, 40 percent then turn to social media to help make a decision. Meanwhile, 46 percent of those who started with social media then turn to search, says the report, titled "The Virtuous Circle: the Role of Search and Social Media in the Purchase Pathway." Just 1 percent of consumers use only social media before buying—suggesting social media "is not yet a stand-alone conduit for the consumer's decision-making process," notes the report.

Why do shoppers start out with search engines? Partly habit, partly ease-of-use, and partly because of the sheer scale of information available, the research found. Shoppers also see search engines as an aid for pricing through the entire buying cycle, and as a source for pinpointing where to buy an item. About one-fourth (26 percent) use search only at the start of the purchase process, while 45 percent said they used it throughout. Eighteen percent use it just at the end.

Chris Copeland, CEO of Group M Search, told MediaPost that the relatively large number of people who only use search at the beginning of the purchase process suggests new strategies for marketers. "That's a surprising data point to us because we would have expected it to be less than those who use it just at the end of the pathway," he said. 

More than three-fourths of those surveyed (86 percent) ranked search as very important in their buying process, more so than social media or company web sites. "Consumers at a ratio of 2 to 1 cite quality and depth of information as reasons for using search versus social media," says the report. "Time may alter these responses, but"—and it continues in boldface type—"as brands think about how and from where to best provide content, search continues to make a compelling case as a valid recipient for initial investment of ad dollars and ongoing optimization effort."

Not surprisingly, social media helps people find options. More than a quarter of those surveyed (28 percent) said sites such as YouTube, Facebook, and Twitter help them learn about new brands and products. Thirty percent said they used social media to eliminate brands from contention.

"There are still many brands who haven't figured out why they're in social media," Copeland said. "We still talk to brands that are trying to determine if they should be in social media. The data suggests the two most important subsets in social are user reviews and category blogs, rather than sites like Facebook, Twitter, and YouTube."