Best Social Media Marketing Tools

What is the best way to tack results with social media marketing?
How does a business owner track their results? Are there tools or software that can show true return on investment numbers to meashure their social media? Example: Google Analytics is one great tool to identify online traffic by impeding a code within your website or blog. What other tools are on the market?
I use Google Analytics as a baseline approach. It gives you a lot of information. The other one I like is Quantcast.com. It gives me all sorts of weird information, such as 9% of my visitors are African American. How they arrive at that number I have no idea.
A better answer to your question is here though:
http://mashable.com/2009/04/19/social-media-analytics/
The basic answer is to Optimize your existing analytics software using plugins or built in tools.
The 4 Most Important Social Media Tools (aka Where Should I Start??)
