Google Analytics has been designed to help you learn even more about where your visitors come from and how they interact with your site.

• It is free. And it offers just as much if not more functionality than most expensive
  visitor tracking solutions!
• You need Analytics to understand how visitors use your site.
• You can identify where visitors leave your check-out or sign-up process and modify it
  to prevent losing leads.
• You can identify which pages and links visitors click on most and spend most time on,
  and position these pages and links appropriately.
• Analytics also tells you which sites users came to your site from.
• You can find out the most popular keywords users type into a search engine to find your site,
  thereby helping your search engine optimisation efforts.
• Visitor segmentation by new vs returning users, geography and referral source will offer
  invaluable insight when planning future business.
• Analytics integrates seamlessly with Google AdWords so that you can have almost
  end-to-end visibility in your search advertising results.
• Analytics allows tracking of other non-search-engine marketing media.
• Analytics will save you money and help you gain more customers.