by Tom Siebert, Friday, Dec 29, 2006 7:00 AM ET

WORD-OF-MOUTH CAN BE A POWERFUL ad force. Marry it to online advertising and you have a potent combo. In fact, social influencers consider online advertising a key factor in their shopping process--second only to Web sites as a source of learning about purchase decisions, according to a study from digital-marketing technology and services company DoubleClick.

Nineteen percent of influencers cited Web advertising as a source of information when they were researching a purchase, compared to 8% among the remainder of the sample. Both segments cited Web sites as their top source of research when they shop, but influencers clearly rely more on the Web than non-influencers, with 40%of influencers citing Web sites for this purpose, versus 31% of non-influencers.

The study, titled "Influencing the Influencers: How Online Advertising and Media Impact Word of Mouth," was done to help companies focus their marketing investments to impact the role "word of mouth" plays in purchase decisions. It is part of a series of reports based on DoubleClick's Touchpoints IV survey of online consumers.

Among the survey respondents, the research identified a segment deemed to be "influencers" and examined how this key segment reaches purchase decisions. To examine the activity of influencers, DoubleClick tried to identify 1,000 influencers among the 6,000-plus Touchpoints respondents: active networkers, subject matter experts, bloggers and online community participants.

Some other key findings of the study include the following:

• Influencers are active consumers of all media, especially the Internet. Asked about a range of different types of media, influencers spent more time reading newspapers and magazines, watching TV and especially using the Internet. Twenty-three percent of non-influencers said that they spent five or more hours a day online, compared to 39% of influencers.
• Influencers pay close attention to advertising, positively and negatively. Compared to non-influencers, influencers were more likely to take some actions to limit or control their exposure to advertising, such as the use of DVRs to fast-forward through TV ads or the use of a pop-up blocker to control their Web experience.

At the same time, they were more apt to agree with positive statements about advertising; 76% agree they are likely to pay attention to advertising when they are shopping for relevant products, compared to 63% of non-influencers. Influencers were also much more likely to do Internet research as a result of ads they saw in traditional media, to talk about ads to their friends, and to acknowledge that ads often contain valuable product information, among other attitudes.

• Influencers embrace emerging media. Influencers are seeing the impact of emerging media, such as video, blogs and messaging: 57% say they watch video online today, compared to 40% of non-influencers; 44% read blogs compared to 28% of non-influencers; 36% access the Web on handheld devices, compared to 21% of non-influencers.

Says Rick Bruner, DoubleClick's director of research and industry relations: "If the question is how can companies spend their marketing dollars to impact word of mouth, the answer is to reach those influencers though advertising. Influencers pay attention to advertising, especially online and in emerging media platforms."

The DoubleClick Touchpoints IV survey also examined how influencers arrived at purchase decisions for different product categories. The results show that the patterns in how influencers and non-influencers shop vary from one type of product to another. For example:

• Overall, car buyers consider Web sites the most valuable source of further learning during the shopping process, ahead of the dealership. However, influencers were more likely to cite Web sites as a factor by eight percentage points.
• Among air travelers, considerably more influencers cited the importance of Web ads (24%) than TV ads (13%). For non-influencers, it was the opposite, with more citing the importance to TV ads (21%) than Web ads (19%).

According to the study, key factors marketers should keep in mind when developing their digital-marketing campaigns to influence the influencers: "Designing ads to be rich in product detail, targeted to the consideration phase of purchasing, can have an echo effect by appealing most to influences. In this way, marketers are not only advertising to prospects, but through influencers to a wider audience. "Consumers shop in different ways for different types of products, and the behavior of influencers also differs in those segments. Marketers that succeed in finding the influencers for their companies and niches should consider investing in original customer research to tailor marketing programs accordingly.

• When building a marketing campaign aiming to reach influencers to tap word-of-mouth potential, digital media should be a critical part of the plan. Emerging media platforms, like online video, mobile Web content and blogs, are highly concentrated with influencers. The study can be downloaded for free at http://www.doubleclick.com/knowledge