It's been determined that people who are regular visitors to social networking sites are a part of a "different spending profile" than non-social network people. Also noted is that social networking traffic typically has a 20% higher income than non-social networking people. Even better for those of us who are (or beging to) using SNs for part of our marketing is the fact that these SN people are typically spending 25% of their disposable income online, vs only %17 for non-social networking traffic. So basically, your traffic from the social network sites are converting much more than simple Google traffic. Here's a graph that shows some of the stats: These are great numbers, and a great direction to go in your SEO.