Social media activity by small business owners is not fully understood in many cases. One reason that popular social media websites are used by businesses of all sizes is to maintain a "competitive presence" rather than making a conscious decision that the specific site in question provides several specific benefits that make it worthwhile.
In fact, many social media websites are viewed in unfavorable terms by consumers in general. In such cases, more harm than good might actually be done by participating actively.
Additionally the SEO (search engine optimization) benefits assumed to be accomplished by linking from a social media site to a company website is often negligible or non-existent.
This all translates to the possibility that small businesses are making social media mistakes and do not even realize it.