http://www.google.com/analytics

This tool lets you have an insight view into all the happenings on your site. Among the free web analytics tool, Google analytics is most preferred choice of among the people.

• It is absolutely free; you just need to create your signup with a google account to start off.

• Implementing google analytics is very fast; just insert the small block of code given by your analytics account.

• Ability to track different traffic source parameters such as search engines, emails, referrers, campaigns and more.

• Can easily create reports in various formats and customize them to suit for your requirements.

• Flexibility to integrate your adwords account into analytics account for better ROI analysis and reporting.

• Benchmarking feature for understanding how your site is performing as compared to your industry metrics.

• Now you can compare your different source data for a short time period without losing anything.

• Track your different campaign, revenue sources and get detail performance metrics.

• Find out which which pages of site are losing required conversion targets and which one is reaching your goals in a funnel view.

• Track visitor traffic from different geographical regions.

• Reports can be configured to sent them directly to specified email.