Facebook use by small business is up so says this article. What they did not say is "has it worked"!
MerchantCircle, an online network of US local business owners, revealed in its quarterly reports that more local businesses are turning to Facebook and other social networking sites like Twitter, as a low-cost option for their marketing efforts.

The survey, conducted with 8,500 random small and local business owners across the U.S, revealed that 70% of these business owners are actively marketing their business through Facebook. This represents a 20% increase over 2010.

Most small businesses running on limited budgets (less than $2,500 annually) and 60% of survey respondents do no plan to raise their budget this year. This makes Facebook an attractive and cost-effective marketing tool for most local business owners.