Small and Medium Business and Social Media

Why are small businesses so reluctant to take up social media? If small business owners are spending personal time on social media, why wouldn't they expand this to include their business? Is there too much emphasis placed on separating personal and business life in small and medium business? Are our business ethics different to our personal ethics and are we nervous about being judged on business ethics by personal values? Will spending in social media really increase in 2010 like this graphic and business surveys would have us believe?