Twitter offers companies a unique method by which to interact with customers, but even many of the most successful small businesses have yet to adequately embrace the social network

Insightpool, a company that helps companies improve their social media efforts, researched the social media footprints of the companies on the annual Inc. 500 list of America's fastest-growing businesses. The researchers looked at what it refers to as each brand's "Social Currency"--defined as social touchpoints between companies and customers on Twitter such as follows, favorites, retweets, and lists.

The results reveal that the Inc. 500 has room to grow on social media. In fact, according to Insightpool's research, only 68 percent of the companies on the list are on Twitter. Of the companies that are on the social site, 69 percent follow fewer than 1,000 accounts, suggesting that there remains greater opportunity to connect with customers. 

Two other important metrics for companies to consider when trying to engage customers on Twitter are favorites and retweets. Of the Inc. 500 companies that have Twitter accounts, just 10 percent are favoriting tweets from other accounts more than 30 times per month, while only 3 percent are retweeting more than 30 times per month. In a similar study of the Fortune 500, Insightpool found that 17 percent of those companies retweet more than 30 times a month. 

"While the Fortune 500 may have more opportunities to rebroadcast positive mentions because of their natural reach, Inc. 500 companies can create new opportunities for retweets by better embracing their existing social media conversations while also cultivating brand new ones from individuals who would love to hear from them," Insightpool founder Adam Wexler says. 

Every small action such as retweeting or following a customer can help build loyalty. Customer engagement, not exclusivity, should be a company's goal, Wexler says.