Google Analytics
Google Analytics is a free service that is available to anyone and is widely considered to be one of, if not the most powerful web analytics solutions for websites.
Google analytics enables everyone in a business to learn a lot of different aspects about their specific area of business. For example, executives of a company can learn what marketing strategies are most effective and which customer segments are the most valuable. The Marketing team can see the traffic on the site, where browsers come from and what they do on a site and also to see how they are able to convert more of the visitors into customers.
It can be used to track as many domain names as you own and also any Facebook or Myspace pages so that you can obtain individual reports for each of these domains.
Another positive aspect of Google analytics is that it enables you to use it on a smaller site, or on a certain amount of pages so that you can try it out to see if you can improve your conversion rates. If it proves to be successful, then it is easy to implement it on the rest of the website.