• by Aaron Baar , December 26, 2008

There may be more than 300 million people in the United States, but when it comes to influencing people's financial decisions, companies may only have to reach a fraction of that.

According to Mediamark Research & Intelligence, a group of 25 million people--about 12% of the U.S. adult population--are considered the key influencers of the rest of the population. In general, this group has an average age of 45.4 and a household income that is only about 4% higher than the national average of $65,000.

However, these so-called "Big Circle Influencers" are 157% more likely to have made 10 or more investment transactions in the past year, 109% more likely to have a securities portfolio worth more than $150,000 and 33% more likely to own a house worth more than $500,000, according to MRI.

"The reason [these people] deserve to be word-of-mouth influencers is not because they earn more, they've made these investments work better," Anne Marie Kelly, senior vice president of marketing and strategic planning at MRI, tells Marketing Daily. "The reason they're talking to people is because they're doing better. They have more credibility."

Finding these Big City Influentials might be more difficult (though Kelly points out that several of them may have their own blogs or other ways to reach a large group of people quickly), but for financial services companies, it can be hugely rewarding, Kelly says.

"It's vital for financial advertisers to be able to identify Big Circle Influentials because these thought leaders advise family, friends, neighbors and colleagues as well as people they don't necessarily know, through viral and social networks," Kelly says. "Targeting on demographics alone would not allow marketers to reach this key segment."