Two small businesses that are using Facebook successfully (fan pages, not ads) are WiseGrass (Paul Stoltzfus) and Grossman's Country Nursery in upstate NY. Both companies realized that they would pull in a small but strong percentage of their customer base; they then used the social media space to educate their customers through multimedia efforts (a plus in the social media arena). In essence, they are using it as a tool to give information away for FREE. It builds customer loyalty and strong word-of-mouth.
Both businesses understand that this is but one small part of their overall strategy. Any business that believes social media should encompass the entire campaign needs to have its head examined. But used correctly, this tool can pack quite a whallop.
Looking forward to your MMM on this.