But not everyone using social networks is worth targeting equally, as it turns out. Instead, there are three types of online personalities that make up just one-fifth of the consumer population but are the key influencers in the purchasing activities of 74% of the population. Gartner calls them Salesmen, Connectors and Mavens.

The Salesmen, Connectors and Mavens are the three key influencer roles in today's social networks, just as they are offline. Salesmen, as you may guess, are defined by their ability to persuade people to purchase or act in certain ways. Salesmen aren't commercial entities, though; they just have the ability to encourage others to action.

Connectors can be split into two sub-groups - "Heavy" and "Light," and are defined by their status as a bridging function between disparate groups of people. Connectors have contacts in a multitude of different social groups and enjoy introducing people to one another.

Mavens are essentially information brokers. They are experts in a particular area and typically field questions from friends and family in need of advice. Often this advice influences purchasing decisions. Mavens, however, aren't necessarily trying to persuade people to purchase; they're just informing them.

Targeting the Key Influencers is Critical

These three roles play part in the purchasing activities of 74% of the population, says Gartner. The survey, taking place in the fourth quarter of 2009, studied nearly 4,000 consumers in 10 key markets and identified six different roles of user behavior. In addition to those mentioned above, there are also Seekers, who are the ones asking others for information, the Self-sufficient, who prefer to find the answers themselves and the Unclassified, who didn't fit into any defined role.

Gartner said it expected that some wouldn't easily fit into these prescribed roles because they may take on different roles when in different social contexts. You may be heralded as the IT expert (aka Maven) among your family, for example, but among your IT colleagues you're more of a Seeker of information. Two-thirds of the population ended up as Unclassified, however, which makes this report's findings and the staggering percentages regarding influence somewhat moot .

What marketers can take away from the study is that there are specific personality types that can be (and should be) targeted when using social networks to promote a brand, company, product or service. Salesmen, Seekers and Connectors are the most effective social network segments to target. This can be done by focusing on both the shopping experience and making information easily available to them. Mavens aren't as useful, because they don't do anything with the information they know unless specifically asked. For these folks (as well as the Self-sufficients), the focus should be primarily on improving the shopping experience.

At the end of the day, none of this is really new information - it just reinforces the fact that when online, consumers behave pretty much as they did prior to the Internet age. Word-of-mouth is still the best way to attract new business, and businesses should target those who like to influence others.