If you're reading this, odds are you have an Internet connection. And if you have an Internet connection, chances are good that you also have a social network profile. Facebook and Myspace—the two most popular social networks—have more than 285 million users worldwide, and Facebook users collectively spend an average of three billion minutes on that site daily.

With all that traffic, these sites are drawing businesses like moths to streetlights. But how should marketers approach promoting themselves on these new venues?