The sites, which are free to join, are more than Facebook meets your checkbook. They offer forums where users discuss spending habits and solicit feedback from peers. In addition, the sites employ interactive tools that help teach users how to budget and search for the best deals based on the spending habits of all users. Useful spending patterns can be determined because the social finance sites are linked to users' banks, brokerages and other accounts. Individual account data remains anonymous and secure.
Just one more place to find that "just right" audience.