There are some steadfast tools for helping to understand website performance and metrics. Google Analytics is a powerful choice for many businesses--as it provides enterprise level functionality at the rock bottom price of free. There is a privacy trade off for using Google Analytics however. There are many other tools to help interpret and gather website analytics, including Omniture, Raven, Urchin, Webtrends, Piwik and more.
Twitter is entering the analytics game. They have introduced a new tool, Twitter Web Analytics, which will help website owners and web designers better understand what Twitter does for you.
Many website owners rely on the information social network for content distribution, which ends up becoming a vital part of their online business agenda. The new tool is based on BackType, a social analytics company that Twitter purchased in July.
The tool is free and currently in beta.