Apart from Google Analytics and any number of log reporting tools, there seems to be more online services offering ways to help you understand your users…

• Crazy Egg €“ visualize your visitors
• ClickTale - because every user has a story 
• TapeFailure - record, review, revise
  

…whilst I’m a fan of using data analysis at times, other approaches to producing great sites and services might include being fab or listening to your customers.